How to read

This changelog lists each bugfix, feature addition, etc in the order they were checked into Fabric’s source code repository. Published releases are bolded, dated and inserted at the appropriate points in the timeline.

To find out the changes included in a given release, simply look at the entries between that release and the previous one from the same release line (e.g. 1.1.4 down through 1.1.3 would be the effective changelog for the 1.1.4 release.)

Bugfixes to older release lines are always forward-ported to newer releases, and this is reflected in the changelog. Thus, the changelog for e.g. 1.2.2 might contain entries for the 1.1 and 1.0 lines as well, because those changes would have also been included in the 1.2 line.


  • 2012-11-06: released Fabric 1.4.4
  • [Feature] #684: Update how task wraps task functions to preserve additional metadata; this allows decorated functions to play nice with Sphinx autodoc. Thanks to Jaka Hudoklin for catch & patch.
  • [Bug] #749: Gracefully work around calls to fabric.version on systems lacking /bin/sh (which causes an OSError in subprocess.Popen calls.)
  • [Bug] #718: isinstance(foo, Bar) is used in main instead of type(foo) == Bar in order to fix some edge cases. Thanks to Mikhail Korobov.
  • [Bug] #693: Fixed edge case where abort driven failures within parallel tasks could result in a top level exception (a KeyError) regarding error handling. Thanks to Marcin Kuźmiński for the report.
  • [Support] #681: Fixed outdated docstring for runs_once which claimed it would get run multiple times in parallel mode. That behavior was fixed in an earlier release but the docs were not updated. Thanks to Jan Brauer for the catch.
  • 2012-07-06: released Fabric 1.4.3
  • 2012-07-06: released Fabric 1.3.8
  • [Bug] #671: reject_unknown_hosts sometimes resulted in a password prompt instead of an abort. This has been fixed. Thanks to Roy Smith for the report.
  • [Bug] #659: Update docs to reflect that local currently honors env.path. Thanks to @floledermann for the catch.
  • [Bug] #652: Show available commands when aborting on invalid command names.
  • [Support] #651: Added note about nesting with statements on Python 2.6+. Thanks to Jens Rantil for the patch.
  • [Bug] #649: Don’t swallow non-abort-driven exceptions in parallel mode. Fabric correctly printed such exceptions, and returned them from execute, but did not actually cause the child or parent processes to halt with a nonzero status. This has been fixed. execute now also honors env.warn_only so users may still opt to call it by hand and inspect the returned exceptions, instead of encountering a hard stop. Thanks to Matt Robenolt for the catch.
  • [Support] #645: Update Sphinx docs to work well when run out of a source tarball as opposed to a Git checkout. Thanks again to @Arfrever for the catch.
  • [Support] #640: (also #644) Update packaging manifest so sdist tarballs include all necessary test & doc files. Thanks to Mike Gilbert and @Arfrever for catch & patch.
  • [Support] #634: Clarified that lcd does no special handling re: the user’s current working directory, and thus relative paths given to it will be relative to os.getcwd(). Thanks to @techtonik for the catch.
  • 2012-05-07: released Fabric 1.4.2
  • 2012-05-07: released Fabric 1.3.7
  • [Bug] #562: Agent forwarding would error out or freeze when multiple uses of the forwarded agent were used per remote invocation (e.g. a single run command resulting in multiple Git or SVN checkouts.) This has been fixed thanks to Steven McDonald and GitHub user @lynxis.
  • [Support] #626: Clarity updates to the tutorial. Thanks to GitHub user m4z for the patches.
  • [Bug] #625: hide/show did not correctly restore prior display settings if an exception was raised inside the block. This has been fixed.
  • [Bug] #624: Login password prompts did not always display the username being authenticated for. This has been fixed. Thanks to Nick Zalutskiy for catch & patch.
  • [Bug] #617: Fix the clean_revert behavior of settings so it doesn’t KeyError for newly created settings keys. Thanks to Chris Streeter for the catch.
  • [Bug] #616: Add port number to the error message displayed upon connection failures.
  • [Bug] #609: (and #564) Document and clean up env.sudo_prefix so it can be more easily modified by users facing uncommon use cases. Thanks to GitHub users 3point2 for the cleanup and SirScott for the documentation catch.
  • [Bug] #610: Change detection of env.key_filename‘s type (added as part of SSH config support in 1.4) so it supports arbitrary iterables. Thanks to Brandon Rhodes for the catch.
  • 2012-04-04: released Fabric 1.4.1
  • 2012-04-04: released Fabric 1.3.6
  • [Bug] #608: Add capture kwarg to rsync_project to aid in debugging rsync problems.
  • [Bug] #607: Allow local to display stdout/stderr when it warns/aborts, if it was capturing them.
  • [Bug] #395: Added an FAQ entry detailing how to handle init scripts which misbehave when a pseudo-tty is allocated.
  • [Bug] #568: execute allowed too much of its internal state changes (to variables such as env.host_string and env.parallel) to persist after execution completed; this caused a number of different incorrect behaviors. execute has been overhauled to clean up its own state changes – while preserving any state changes made by the task being executed.
  • [Bug] #584: upload_project did not take explicit remote directory location into account when untarring, and now uses cd to address this. Thanks to Ben Burry for the patch.
  • [Bug] #458: with_settings did not perfectly match settings, re: ability to inline additional context managers. This has been corrected. Thanks to Rory Geoghegan for the patch.
  • [Bug] #499: contrib.files.first used an outdated function signature in its wrapped exists call. This has been fixed. Thanks to Massimiliano Torromeo for catch & patch.
  • [Bug] #551: --list output now detects terminal window size and truncates (or doesn’t truncate) accordingly. Thanks to Horacio G. de Oro for the initial pull request.
  • [Bug] #572: Parallel task aborts (as oppposed to unhandled exceptions) now correctly print their abort messages instead of tracebacks, and cause the parent process to exit with the correct (nonzero) return code. Thanks to Ian Langworth for the catch.
  • [Bug] #306: Remote paths now use posixpath for a separator. Thanks to Jason Coombs for the patch.
  • 2012-02-13: released Fabric 1.4.0
  • 2012-02-13: released Fabric 1.3.5
  • 2012-02-13: released Fabric 1.2.6
  • 2012-02-13: released Fabric 1.1.8
  • [Bug] #495: Fixed documentation example showing how to subclass Task. Thanks to Brett Haydon for the catch and Mark Merritt for the patch.
  • [Bug] #410: Fixed a bug where using the task decorator inside/under another decorator such as hosts could cause that task to become invalid when invoked by name (due to how old-style vs new-style tasks are detected.) Thanks to Dan Colish for the initial patch.
  • [Feature] #559: rsync_project now allows users to append extra SSH-specific arguments to rsync‘s --rsh flag.
  • [Feature] #138: env.port may now be written to at fabfile module level to set a default nonstandard port number. Previously this value was read-only.
  • [Feature] #3: Fabric can now load a subset of SSH config functionality directly from your local ~/.ssh/config if env.use_ssh_config is set to True. See Leveraging native SSH config files for details. Thanks to Kirill Pinchuk for the initial patch.
  • [Feature] #12: Added the ability to try connecting multiple times to temporarily-down remote systems, instead of immediately failing. (Default behavior is still to only try once.) See env.timeout and env.connection_attempts for controlling both connection timeouts and total number of attempts. reboot has also been overhauled (but practically deprecated – see its updated docs.)
  • [Feature] #474: execute now allows you to access the executed task’s return values, by itself returning a dictionary whose keys are the host strings executed against.
  • [Bug] #487: Overhauled the regular expression escaping performed in append and contains to try and handle more corner cases. Thanks to Neilen Marais for the patch.
  • [Support] #532: Reorganized and cleaned up the output of fab --help.
  • [Feature] #8: Added --skip-bad-hosts/env.skip_bad_hosts option to allow skipping past temporarily down/unreachable hosts.
  • [Feature] #13: Env vars may now be set at runtime via the new --set command-line flag.
  • [Feature] #506: A new output alias, commands, has been added, which allows hiding remote stdout and local “running command X” output lines.
  • [Feature] #72: SSH agent forwarding support has made it into Fabric’s SSH library, and hooks for using it have been added (disabled by default; use -A or env.forward_agent to enable.) Thanks to Ben Davis for porting an existing Paramiko patch to ssh and providing the necessary tweak to Fabric.
  • 2012-01-12: released Fabric 1.3.4
  • [Bug] #492: @parallel did not automatically trigger linewise output, as was intended. This has been fixed. Thanks to Brandon Huey for the catch.
  • [Bug] #510: Parallel mode is incompatible with user input, such as password/hostname prompts, and was causing cryptic Operation not supported by device errors when such prompts needed to be displayed. This behavior has been updated to cleanly and obviously abort instead.
  • [Bug] #494: Fixed regression bug affecting some env values such as env.port under parallel mode. Symptoms included rsync_project bailing out due to a None port value when run under @parallel. Thanks to Rob Terhaar for the report.
  • [Bug] #339: Don’t show imported colors members in --list output. Thanks to Nick Trew for the report.
  • 2011-11-23: released Fabric 1.3.3
  • 2011-11-23: released Fabric 1.2.5
  • 2011-11-23: released Fabric 1.1.7
  • [Bug] #441: Specifying a task module as a task on the command line no longer blows up but presents the usual “no task by that name” error message instead. Thanks to Mitchell Hashimoto for the catch.
  • [Bug] #475: Allow escaping of equals signs in per-task args/kwargs.
  • [Bug] #450: Improve traceback display when handling ImportError for dependencies. Thanks to David Wolever for the patches.
  • [Bug] #446: Add QNX to list of secondary-case sed targets. Thanks to Rodrigo Madruga for the tip.
  • [Bug] #443: exists didn’t expand tildes; now it does. Thanks to Riccardo Magliocchetti for the patch.
  • [Bug] #437: with_settings now correctly preserves the wrapped function’s docstring and other attributes. Thanks to Eric Buckley for the catch and Luke Plant for the patch.
  • [Bug] #400: Handle corner case of systems where pwd.getpwuid raises KeyError for the user’s UID instead of returning a valid string. Thanks to Dougal Matthews for the catch.
  • [Bug] #397: Some poorly behaved objects in third party modules triggered exceptions during Fabric’s “classic or new-style task?” test. A fix has been added which tries to work around these.
  • [Bug] #341: append incorrectly failed to detect that the line(s) given already existed in files hidden to the remote user, and continued appending every time it ran. This has been fixed. Thanks to Dominique Peretti for the catch and Martin Vilcans for the patch.
  • [Bug] #342: Combining cd with put and its use_sudo keyword caused an unrecoverable error. This has been fixed. Thanks to Egor M for the report.
  • [Bug] #482: Parallel mode should imply linewise output; omission of this behavior was an oversight.
  • [Bug] #230: Fix regression re: combo of no fabfile & arbitrary command use. Thanks to Ali Saifee for the catch.
  • 2011-11-07: released Fabric 1.3.2
  • 2011-11-07: released Fabric 1.2.4
  • 2011-11-07: released Fabric 1.1.6
  • [Support] #459: Update our files to note that PyCrypto released 2.4.1, which fixes the setuptools problems.
  • [Support] #467: (also #468, #469) Handful of documentation clarification tweaks. Thanks to Paul Hoffman for the patches.
  • 2011-10-24: released Fabric 1.3.1
  • [Bug] #457: Ensured that Fabric fast-fails parallel tasks if any child processes encountered errors. Previously, multi-task invocations would continue to the 2nd, etc task when failures occurred, which does not fit with how Fabric usually behaves. Thanks to Github user sdcooke for the report and Morgan Goose for the fix.
  • 2011-10-23: released Fabric 1.3.0
  • 2011-10-23: released Fabric 1.2.3
  • 2011-10-23: released Fabric 1.1.5
  • 2011-10-23: released Fabric 1.0.5
  • [Support] #275: To support an edge use case of the features released in #19, and to lay the foundation for #275, we have forked Paramiko into the Python ‘ssh’ library and changed our dependency to it for Fabric 1.3 and higher. This may have implications for the more uncommon install use cases, and package maintainers, but we hope to iron out any issues as they come up.
  • [Bug] #323: put forgot how to expand leading tildes in the remote file path. This has been corrected. Thanks to Piet Delport for the catch.
  • [Feature] #21: It is now possible, using the new execute API call, to execute task objects (by reference or by name) from within other tasks or in library mode. execute honors the other tasks’ hosts/roles decorators, and also supports passing in explicit host and/or role arguments.
  • [Feature] #19: Tasks may now be optionally executed in parallel. Please see the parallel execution docs for details. Major thanks to Morgan Goose for the initial implementation.
  • [Bug] #182: During display of remote stdout/stderr, Fabric occasionally printed extraneous line prefixes (which in turn sometimes overwrote wrapped text.) This has been fixed.
  • [Bug] #430: Tasks decorated with runs_once printed extraneous ‘Executing...’ status lines on subsequent invocations. This is noisy at best and misleading at worst, and has been corrected. Thanks to Jacob Kaplan-Moss for the report.
  • 2011-09-01: released Fabric 1.2.2
  • 2011-09-01: released Fabric 1.1.4
  • 2011-09-01: released Fabric 1.0.4
  • [Bug] #252: settings would silently fail to set env values for keys which did not exist outside the context manager block. It now works as expected. Thanks to Will Maier for the catch and suggested solution.
  • [Support] #393: Fixed a typo in an example code snippet in the task docs. Thanks to Hugo Garza for the catch.
  • [Bug] #396: --shortlist broke after the addition of --list-format and no longer displayed the short list format correctly. This has been fixed.
  • [Bug] #373: Re-added missing functionality preventing host exclusion from working correctly.
  • [Bug] #303: Updated terminal size detection to correctly skip over non-tty stdout, such as when running fab taskname | other_command.
  • 2011-08-21: released Fabric 1.2.1
  • 2011-08-21: released Fabric 1.1.3
  • 2011-08-21: released Fabric 1.0.3
  • [Bug] #417: abort_on_prompts would incorrectly abort when set to True, even if both password and host were defined. This has been fixed. Thanks to Valerie Ishida for the report.
  • [Support] #416: Updated documentation to reflect move from Redmine to Github.
  • [Bug] #389: Fixed/improved error handling when Paramiko import fails. Thanks to Brian Luft for the catch.
  • 2011-07-12: released Fabric 1.2.0
  • [Feature] #22: Enhanced @task to add aliasing, per-module default tasks, and control over the wrapping task class. Thanks to Travis Swicegood for the initial work and collaboration.
  • [Bug] #380: Improved unicode support when testing objects for being string-like. Thanks to Jiri Barton for catch & patch.
  • [Support] #382: Experimental overhaul of changelog formatting & process to make supporting multiple lines of development less of a hassle.
  • 2011-07-07: released Fabric 1.1.2 (see below for details)
  • 2011-06-24: released Fabric 1.0.2 (see below for details)


The content below this section comes from older versions of Fabric which wrote out changelogs to individual, undated files. They have been concatenated and preserved here for historical reasons, and may not be in strict chronological order.

Changes in version 1.1.2 (2011-07-07)


  • #375: The logic used to separate tasks from modules when running fab --list incorrectly considered task classes implementing the mapping interface to be modules, not individual tasks. This has been corrected. Thanks to Vladimir Mihailenco for the catch.

Changes in version 1.1.1 (2011-06-29)


  • The public API for Task mentioned use of the run() method, but Fabric’s main execution loop had not been updated to look for and call it, forcing users who subclassed Task to define __call__() instead. This was an oversight and has been corrected.

    See also

    Task subclasses

Changes in version 1.1 (2011-06-24)

This page lists all changes made to Fabric in its 1.1.0 release.


This release also includes all applicable changes from the 1.0.2 release.


  • #76: New-style tasks have been added. With the addition of the task decorator and the Task class, you can now “opt-in” and explicitly mark task functions as tasks, and Fabric will ignore the rest. The original behavior (now referred to as “classic” tasks) will still take effect if no new-style tasks are found. Major thanks to Travis Swicegood for the original implementation.
  • #56: Namespacing is now possible: Fabric will crawl imported module objects looking for new-style task objects and build a dotted hierarchy (tasks named e.g. web.deploy or, allowing for greater organization. See Namespaces for details. Thanks again to Travis Swicegood.

Feature additions

  • #10: upload_project now allows control over the local and remote directory paths, and has improved error handling. Thanks to Rodrigue Alcazar for the patch.
  • As part of #56 (highlighted above), added --list-format to allow specification of a nested output format from --list.
  • #107: require‘s provided_by kwarg now accepts iterables in addition to single values. Thanks to Thomas Ballinger for the patch.
  • #117: upload_template now supports the put flags mirror_local_mode and mode. Thanks to Joe Stump for the suggestion and Thomas Ballinger for the patch.
  • #154: sed now allows customized regex flags to be specified via a new flags parameter. Thanks to Nick Trew for the suggestion and Morgan Goose for initial implementation.
  • #170: Allow exclusion of specific hosts from the final run list. Thanks to Casey Banner for the suggestion and patch.
  • #189: Added --abort-on-prompts/env.abort_on_prompts to allow a more non-interactive behavior, aborting/exiting instead of trying to prompt the running user. Thanks to Jeremy Avnet and Matt Chisholm for the initial patch.
  • #273: upload_template now offers control over whether it attempts to create backups of pre-existing destination files. Thanks to Ales Zoulek for the suggestion and initial patch.
  • #283: Added the with_settings decorator to allow application of env var settings to an entire function, as an alternative to using the settings context manager. Thanks to Travis Swicegood for the patch.
  • #353: Added --keepalive/env.keepalive to allow specification of an SSH keepalive parameter for troublesome network connections. Thanks to Mark Merritt for catch & patch.


  • #115: An implementation detail causing host lists to lose order when deduped by the fab execution loop, has been patched to preserve order instead. So e.g. fab -H a,b,c (or setting env.hosts = ['a', 'b', 'c']) will now always run on a, then b, then c. Previously, there was a chance the order could get mixed up during deduplication. Thanks to Rohit Aggarwal for the report.
  • #345: contains returned the stdout of its internal grep command instead of success/failure, causing incorrect behavior when stderr exists and is combined with stdout. This has been corrected. Thanks to Szymon Reichmann for catch and patch.

Documentation updates

  • Documentation for task declaration has been moved from Execution model into its own docs page, Defining tasks, as a result of the changes added in #76 and #56.
  • #184: Make the usage of rsync_project‘s local_dir argument more obvious, regarding its use in the rsync call. (Specifically, so users know they can pass in multiple, space-joined directory names instead of just one single directory.)


  • #307: A whole pile of minor PEP8 tweaks. Thanks to Markus Gattol for highlighting the pep8 tool and to Rick Harding for the patch.
  • #314: Test utility decorator improvements. Thanks to Rick Harding for initial catch & patch.

Changes in version 1.0.2 (2011-06-24)


This release also includes all applicable changes from the 0.9.7 release.


  • #258: Bugfix to a previous, incorrectly applied fix regarding local on Windows platforms.
  • #324: Update run/sudo‘s combine_stderr kwarg so that it correctly overrides the global setting in all cases. This required changing its default value to None, but the default behavior (behaving as if the setting were True) has not changed. Thanks to Matthew Woodcraft and Connor Smith for the catch.
  • #337: Fix logic bug in put preventing use of mirror_local_mode. Thanks to Roman Imankulov for catch & patch.
  • #352 (also #320): Seemingly random issues with output lockup and input problems (e.g. sudo prompts incorrectly rejecting passwords) appear to have been caused by an I/O race condition. This has been fixed. Thanks to Max Arnold and Paul Oswald for the detailed reports and to Max for the diagnosis and patch.


  • Updated the API documentation for cd to explicitly point users to lcd for modifying local paths.
  • Clarified the behavior of rsync_project re: how trailing slashes in local_dir affect remote_dir. Thanks to Mark Merritt for the catch.

Changes in version 1.0.1 (2011-03-27)


This release also includes all applicable changes from the 0.9.5 release.


  • #301: Fixed a bug in local‘s behavior when capture=False and output.stdout (or .stderr) was also False. Thanks to Chris Rose for the catch.
  • #310: Update edge case in put where using the mode kwarg alongside use_sudo=True runs a hidden sudo command. The mode kwarg needs to be octal but was being interpolated in the sudo call as a string/integer. Thanks to Adam Ernst for the catch and suggested fix.
  • #311: append was supposed to have its partial kwarg’s default flipped from True to False. However, only the documentation was altered. This has been fixed. Thanks to Adam Ernst for bringing it to our attention.
  • #312: Tweak internal I/O related loops to prevent high CPU usage and poor screen-printing behavior on some systems. Thanks to Kirill Pinchuk for the initial patch.
  • #320: Some users reported problems with dropped input, particularly while entering sudo passwords. This was fixed via the same change as for #312.


  • Added a missing entry for env.path in the usage documentation.

Changes in version 1.0 (2011-03-04)

This page lists all changes made to Fabric in its 1.0.0 release.


  • #7: run/sudo now allow full interactivity with the remote end. You can interact with remote prompts and similar interfaces, making certain tasks much easier, and freeing you from the need to find noninteractive solutions if you don’t want to. See Interaction with remote programs for more on these changes.
  • put and get received many updates, including but not limited to: recursion, globbing, inline sudo capability, and increased control over local file paths. See the individual ticket line-items below for details. Erich Heine (sophacles on IRC) played a large part in implementing and/or collecting these changes and deserves much of the credit.
  • Added functionality for loading fabfiles which are Python packages (directories) instead of just modules (single files). This allows for easier organization of nontrivial fabfiles and paves the way for task namespacing in the near future. See Fabfile discovery for details.
  • #185: Mostly of interest to those contributing to Fabric itself, Fabric now leverages Paramiko to provide a stub SSH and SFTP server for use during runs of our test suite. This makes quick, configurable full-stack testing of Fabric (and, to an extent, user fabfiles) possible.

Backwards-incompatible changes

The below changes are backwards incompatible and have the potential to break your 0.9.x based fabfiles!

  • contains and append previously had the filename argument in the second position, whereas all other functions in the contrib.files module had filename as the first argument. These two functions have been brought in line with the rest of the module.
  • sed now escapes single-quotes and parentheses in addition to forward slashes, in its before and after kwargs. Related to, but not entirely contained within, #159.
  • The user and pty kwargs in sudo‘s signature have had their order swapped around to more closely match run.
  • As part of the changes made in #7, run and sudo have had the default value of their pty kwargs changed from False to True. This, plus the addition of the combine_stderr kwarg/env var, may result in significant behavioral changes in remote programs which operate differently when attached to a tty.
  • #61: put and get now honor the remote current-working-directory changes applied by cd. Previously they would always treat relative remote paths as being relative to the remote home directory.
  • #79: get now allows increased control over local filenames when downloading single or multiple files. This is backwards incompatible because the default path/filename for downloaded files has changed. Thanks to Juha Mustonen, Erich Heine and Max Arnold for brainstorming solutions.
  • #88: local has changed the default value of its capture kwarg, from True to False. This was changed in order to be more intuitive, at the cost of no longer defaulting to the same rich return value as in run/sudo (which is still available by specifying capture=True.)
  • #121: put will no longer automatically attempt to mirror local file modes. Instead, you’ll need to specify mirror_local_mode=True to get this behavior. Thanks to Paul Smith for a patch covering part of this change.
  • #172: append has changed the default value of its partial kwarg from True to False in order to be safer/more intuitive.
  • #221: runs_once now memoizes the wrapped task’s return value and returns that value on subsequent invocations, instead of returning None. Thanks to Jacob Kaplan-Moss and Travis Swicegood for catch + patch.

Feature additions

  • Prerelease versions of Fabric (starting with the 1.0 prereleases) will now print the Git SHA1 hash of the current checkout, if the user is working off of a Git clone of the Fabric source code repository.
  • Added path context manager for modifying commands’ effective $PATH.
  • Added convenience .succeeded attribute to the return values of run/sudo/local which is simply the opposite of the .failed attribute. (This addition has also been backported to Fabric’s 0.9 series.)
  • Refactored SSH disconnection code out of the main fab loop into disconnect_all, allowing library users to avoid problems with non-fabfile Python scripts hanging after execution finishes.
  • #2: Added use_sudo kwarg to put to allow uploading of files to privileged locations. Thanks to Erich Heine and IRC user npmap for suggestions and patches.
  • #23: Added prefix context manager for easier management of persistent state across commands.
  • #27: Added environment variable (always_use_pty) and command-line flag (--no-pty) for global control over the run/sudo pty argument.
  • #28: Allow shell-style globbing in get. Thanks to Erich Heine and Max Arnold.
  • #55: run, sudo and local now provide access to their standard error (stderr) as an attribute on the return value, alongside e.g. .failed.
  • #148: local now returns the same “rich” string object as run/sudo do, so that it is a string containing the command’s stdout (if capture=True) or the empty string (if capture=False) which exposes the .failed and .return_code attributes, and so forth.
  • #151: Added a puts utility function, which allows greater control over fabfile-generated (as opposed to Fabric-generated) output. Also added fastprint, an alias to puts allowing for convenient unbuffered, non-newline-terminated printing.
  • #192: Added per-user/host password cache to assist in multi-connection scenarios.
  • #193: When requesting a remote pseudo-terminal, use the invoking terminal’s dimensions instead of going with the default.
  • #217: get/put now accept file-like objects as well as local file paths for their local_path arguments.
  • #245: Added the lcd context manager for controlling local‘s current working directory and put/get‘s local working directories.
  • #274: put/get now have return values which may be iterated over to access the paths of files uploaded remotely or downloaded locally, respectively. These return values also allow access to .failed and .succeeded attributes, just like run and friends. (In this case, .failed is actually a list itself containing any paths which failed to transfer, which naturally acts as a boolean as well.)

Documentation updates

  • API, tutorial and usage docs updated with the above new features.
  • README now makes the Python 2.5+ requirement up front and explicit; some folks were still assuming it would run on Python 2.4.
  • Added a link to Python’s documentation for string interpolation in upload_template‘s docstring.

Changes in version 0.9.7 (2011-06-23)

The following changes were implemented in Fabric 0.9.7:


  • #329: reboot would have problems reconnecting post-reboot (resulting in a traceback) if env.host_string was not fully-formed (did not contain user and port specifiers.) This has been fixed.

Changes in version 0.9.6 (2011-04-29)

The following changes were implemented in Fabric 0.9.6:


  • #347: append incorrectly tested for str instead of types.StringTypes, causing it to split up Unicode strings as if they were one character per line. This has been fixed.

Changes in version 0.9.5 (2011-03-21)

The following changes were implemented in Fabric 0.9.5:


  • #37: Internal refactoring of a Paramiko call from _transport to get_transport().
  • #258: Modify subprocess call on Windows platforms to avoid space/quote problems in local. Thanks to Henrik Heimbuerger and Raymond Cote for catch + suggested fixes.
  • #261: Fix bug in comment which truncated regexen ending with $. Thanks to Antti Kaihola for the catch.
  • #264: Fix edge case in reboot by gracefully clearing connection cache. Thanks to Jason Gerry for the report & troubleshooting.
  • #268: Allow for @ symbols in usernames, which is valid on some systems. Fabric’s host-string parser now splits username and hostname at the last @ found instead of the first. Thanks to Thadeus Burgess for the report.
  • #287: Fix bug in password prompt causing occasional tracebacks. Thanks to Antti Kaihola for the catch and Rick Harding for testing the proposed solution.
  • #288: Use temporary files to work around the lack of a -i flag in OpenBSD and NetBSD sed. Thanks to Morgan Lefieux for catch + patches.
  • #305: Strip whitespace from hostnames to help prevent user error. Thanks to Michael Bravo for the report and Rick Harding for the patch.
  • #316: Use of settings with key names not previously set in env no longer raises KeyErrors. Whoops. Thanks to Adam Ernst for the catch.

Documentation updates

  • #228: Added description of the PyCrypto + pip + Python 2.5 problem to the documentation and removed the Python 2.5 check from
  • #291: Updated the PyPM-related install docs re: recent changes in PyPM and its download URLs. Thanks to Sridhar Ratnakumar for the patch.

Changes in version 0.9.4 (2011-02-18)

The following changes were implemented in Fabric 0.9.4:

Feature additions

  • Added documentation for using Fabric as a library.
  • Mentioned our Twitter account on the main docs page.
  • #290: Added escape kwarg to append to allow control over previously automatic single-quote escaping.

Changes in version 0.9.3 (2010-11-12)

The following changes were implemented in Fabric 0.9.3:

Feature additions

  • #255: Added stderr and succeeded attributes to local.
  • #254: Backported the .stderr and .succeeded attributes on run/sudo return values, from the Git master/pre-1.0 branch. Please see those functions’ API docs for details.


  • #228: We discovered that the pip + PyCrypto installation problem was limited to Python 2.5 only, and have updated our accordingly.
  • #230: Arbitrary or remainder commands (fab <opts> -- <run command here>) will no longer blow up when invoked with no fabfile present. Thanks to IRC user orkaa for the report.
  • #242: Empty string values in task CLI args now parse correctly. Thanks to Aaron Levy for the catch + patch.

Documentation updates

  • #239: Fixed typo in execution usage docs. Thanks to Pradeep Gowda and Turicas for the catch.

Changes in version 0.9.2 (2010-09-06)

The following changes were implemented in Fabric 0.9.2:

Feature additions

  • The reboot operation has been added, providing a way for Fabric to issue a reboot command and then reconnect after the system has restarted.
  • python test now runs Fabric’s test suite (provided you have all the prerequisites from the requirements.txt installed). Thanks to Eric Holscher for the patch.
  • Added functionality for loading fabfiles which are Python packages (directories) instead of just modules (single files.) See Fabfile discovery.
  • Added output lines informing the user of which tasks are being executed (e.g. [myserver] Executing task 'foo'.)
  • Added support for lazy (callable) role definition values in env.roledefs.
  • Added contrib.django module with basic Django integration.
  • env.local_user was added, providing easy and permanent access to the local system username, even if an alternate remote username has been specified.
  • #29: Added support for arbitrary command-line-driven anonymous tasks via fab [options] -- [shell command]. See Arbitrary remote shell commands.
  • #52: Full tracebacks during aborts are now displayed if the user has opted to see debug-level output.
  • #101: Added colors module with basic color output support. (#101 is still open: we plan to leverage the new module in Fabric’s own output in the future.)
  • #137: Commas used to separate per-task arguments may now be escaped with a backslash. Thanks to Erich Heine for the patch.
  • #144: hosts (and roles) will now expand a single, iterable argument instead of requiring one to use e.g. @hosts(*iterable).
  • #151: Added a puts utility function, which allows greater control over fabfile-generated (as opposed to Fabric-generated) output. Also added fastprint, an alias to puts allowing for convenient unbuffered, non-newline-terminated printing.
  • #208: Users rolling their own shell completion or who otherwise find themselves performing text manipulation on the output of --list may now use --shortlist to get a plain, newline-separated list of task names.


  • The interactive “what host to connect to?” prompt now correctly updates the appropriate environment variables (hostname, username, port) based on user input.
  • Fixed a bug where Fabric’s own internal fabfile would pre-empt the user’s fabfile due to a PYTHONPATH order issue. User fabfiles are now always loaded at the front of the PYTHONPATH during import.
  • Disabled some DeprecationWarnings thrown by Paramiko when that library is imported into Fabric under Python 2.6.
  • #44, #63: Modified rsync_project to honor the SSH port and identity file settings. Thanks to Mitch Matuson and Morgan Goose.
  • #123: Removed Cygwin from the “are we on Windows” test; now, only Python installs whose sys.platform says 'win32' will use Windows-only code paths (e.g. importing of pywin32).

Documentation updates

  • Added a few new items to the FAQ.
  • #173: Simple but rather embarrassing typo fix in README. Thanks to Ted Nyman for the catch.
  • #194: Added a note to the install docs about a possible edge case some Windows 64-bit Python users may encounter.
  • #216: Overhauled the process backgrounding FAQ to include additional techniques and be more holistic.

Packaging updates

  • #86, #158: Removed the bundled Paramiko 1.7.4 and updated the to require Paramiko >=1.7.6. This lets us skip the known-buggy Paramiko 1.7.5 while getting some much needed bugfixes in Paramiko 1.7.6.

Changes in version 0.9.1 (2010-05-28)

The following changes were implemented in Fabric 0.9.1:

Feature additions

  • #82: append now offers a partial kwarg allowing control over whether the “don’t append if given text already exists” test looks for exact matches or not. Thanks to Jonas Nockert for the catch and discussion.
  • #112: fab --list now prints out the fabfile’s module-level docstring as a header, if there is one.
  • #141: Added some more CLI args/env vars to allow user configuration of the Paramiko connect call – specifically no_agent and no_keys.


  • #75: fab, when called with no arguments or (useful) options, now prints help, even when no fabfile can be found. Previously, calling fab in a location with no fabfile would complain about the lack of fabfile instead of displaying help.
  • #130: Context managers now correctly clean up env if they encounter an exception. Thanks to Carl Meyer for catch + patch.
  • #132: local now calls strip on its stdout, matching the behavior of run/sudo. Thanks to Carl Meyer again on this one.
  • #166: cd now correctly overwrites env.cwd when given an absolute path, instead of naively appending its argument to env.cwd‘s previous value.

Documentation updates

  • A number of small to medium documentation tweaks were made which had no specific Redmine ticket. The largest of these is the addition of the FAQ to the Sphinx documentation instead of storing it as a source-only text file. (Said FAQ was also slightly expanded with new FAQs.)
  • #17: Added note to FAQ re: use of dtach as alternative to screen. Thanks to Erich Heine for the tip.
  • #64: Updated installation docs to clarify where package maintainers should be downloading tarballs from. Thanks to James Pearson for providing the necessary perspective.
  • #95: Added a link to a given version’s changelog on the PyPI page (technically, to the long_description field).
  • #110: Alphabetized the CLI argument command reference. Thanks to Erich Heine.
  • #120: Tweaked documentation, help strings to make it more obvious that fabfiles are simply Python modules.
  • #127: Added note to install docs re: ActiveState’s PyPM. Thanks to Sridhar Ratnakumar for the tip.

Changes in version 0.9 (2009-11-08)

This document details the various backwards-incompatible changes made during Fabric’s rewrite between versions 0.1 and 0.9. The codebase has been almost completely rewritten and reorganized and an attempt has been made to remove “magical” behavior and make things more simple and Pythonic; the fab command-line component has also been redone to behave more like a typical Unix program.

Major changes

You’ll want to at least skim the entire document, but the primary changes that will need to be made to one’s fabfiles are as follows:


You will need to explicitly import any and all methods or decorators used, at the top of your fabfile; they are no longer magically available. Here’s a sample fabfile that worked with 0.1 and earlier:

@hosts('a', 'b')
def my_task():
    run('ls /var/www')
    sudo('mkdir /var/www/newsite')

The above fabfile uses hosts, run and sudo, and so in Fabric 0.9 one simply needs to import those objects from the new API module fabric.api:

from fabric.api import hosts, run, sudo

@hosts('a', 'b')
def my_task():
    run('ls /var/www')
    sudo('mkdir /var/www/newsite')

You may, if you wish, use from fabric.api import *, though this is technically not Python best practices; or you may import directly from the Fabric submodules (e.g. from fabric.decorators import hosts.) See Fabfile construction and use for more information.

Python version

Fabric started out Python 2.5-only, but became largely 2.4 compatible at one point during its lifetime. Fabric is once again only compatible with Python 2.5 or newer, in order to take advantage of the various new features and functions available in that version.

With this change we’re setting an official policy to support the two most recent stable releases of the Python 2.x line, which at time of writing is 2.5 and 2.6. We feel this is a decent compromise between new features and the reality of operating system packaging concerns. Given that most users use Fabric from their workstations, which are typically more up-to-date than servers, we’re hoping this doesn’t cut out too many folks.

Finally, note that while we will not officially support a 2.4-compatible version or fork, we may provide a link to such a project if one arises.

Environment/config variables

The config object previously used to access and set internal state (including Fabric config options) has been renamed to env, but otherwise remains mostly the same (it allows both dictionary and object-attribute style access to its data.) env resides in the state submodule and is importable via fabric.api, so where before one might have seen fabfiles like this:

def my_task(): = 'bar'

one will now be explicitly importing the object like so:

from fabric.api import env

def my_task(): = 'bar'

Execution mode

Fabric’s default mode of use, in prior versions, was what we called “broad mode”: your tasks, as Python code, ran only once, and any calls to functions that made connections (such as run or sudo) would run once per host in the current host list. We also offered “deep mode”, in which your entire task function would run once per host.

In Fabric 0.9, this dichotomy has been removed, and “deep mode” is the method Fabric uses to perform all operations. This allows you to treat your Fabfiles much more like regular Python code, including the use of if statements and so forth, and allows operations like run to unambiguously return the output from the server.

Other modes of execution such as the old “broad mode” may return as Fabric’s internals are refactored and expanded, but for now we’ve simplified things, and deep mode made the most sense as the primary mode of use.

“Lazy” string interpolation

Because of how Fabric used to run in “broad mode” (see previous section) a special string formatting technique – the use of a bash-like dollar sign notation, e.g. "hostname: $(fab_host)" – had to be used to allow the current state of execution to be represented in one’s operations. This is no longer necessary and has been removed. Because your tasks are executed once per host, you may build strings normally (e.g. with the % operator) and refer to env.host_string, env.user and so forth.

For example, Fabric 0.1 had to insert the current username like so:

print("Your current username is $(fab_user)")

Fabric 0.9 and up simply reference env variables as normal:

print("Your current username is %s" % env.user)

As with the execution modes, a special string interpolation function or method that automatically makes use of env values may find its way back into Fabric at some point if a need becomes apparent.

Other backwards-incompatible changes

In no particular order:

  • The Fabric config file location used to be ~/.fabric; in the interests of honoring Unix filename conventions, it’s now ~/.fabricrc.

  • The old config object (now env) had a getAny method which took one or more key strings as arguments, and returned the value attached to the first valid key. This method still exists but has been renamed to first.

  • Environment variables such as fab_host have been renamed to simply e.g. host. This looks cleaner and feels more natural, and requires less typing. Users will naturally need to be careful not to override these variables, but the same holds true for e.g. Python’s builtin methods and types already, so we felt it was worth the tradeoff.

  • Fabric’s version header is no longer printed every time the program runs; you should now use the standard --version/-V command-line options to print version and exit.

  • The old about command has been removed; other Unix programs don’t typically offer this. Users can always view the license and warranty info in their respective text files distributed with the software.

  • The old help command is now the typical Unix options -h/--help.

    • Furthermore, there is no longer a listing of Fabric’s programming API available through the command line – those topics impact fabfile authors, not fab users (even though the former is a subset of the latter) and should stay in the documentation only.
  • prompt‘s primary function is now to return a value to the caller, although it may still optionally store the entered value in env as well.

  • prompt now considers the empty string to be valid input; this allows other functions to wrap prompt and handle “empty” input on their own terms.

  • In addition to the above changes, prompt has been updated to behave more obviously, as its previous behavior was confusing in a few ways:

    • It will now overwrite pre-existing values in the environment dict, but will print a warning to the user if it does so.
    • Additionally, (and this appeared to be undocumented) the default argument could take a callable as well as a string, and would simply set the default message to the return value if a callable was given. This seemed to add unnecessary complexity (given that users may call e.g. prompt(blah, msg, default=my_callable()) so it has been removed.
  • When connecting, Fabric used to use the undocumented fab_pkey env variable as a method of passing in a Paramiko PKey object to the SSH client’s connect method. This has been removed in favor of an ssh-like -i option, which allows one to specify a private key file to use; that should generally be enough for most users.

  • download is now get in order to match up with put (the name mismatch was due to get being the old method of getting env vars.)

  • The noshell argument to sudo (added late in its life to previous Fabric versions) has been renamed to shell (defaults to True, so the effective behavior remains the same) and has also been extended to the run operation.

    • Additionally, the global sudo_noshell option has been renamed to use_shell and also applies to both run and sudo.
  • local_per_host has been removed, as it only applied to the now-removed “broad mode”.

  • load has been removed; Fabric is now “just Python”, so use Python’s import mechanisms in order to stitch multiple fabfiles together.

  • abort is no longer an “operation” per se and has been moved to fabric.utils. It is otherwise the same as before, taking a single string message, printing it to the user and then calling sys.exit(1).

  • rsyncproject and upload_project have been moved into fabric.contrib (specifically, fabric.contrib.project), which is intended to be a new tree of submodules for housing “extra” code which may build on top of the core Fabric operations.

  • invoke has been turned on its head, and is now the runs_once decorator (living in fabric.decorators). When used to decorate a function, that function will only execute one time during the lifetime of a fab run. Thus, where you might have used invoke multiple times to ensure a given command only runs once, you may now use runs_once to decorate the function and then call it multiple times in a normal fashion.

  • It looks like the regex behavior of the validate argument to prompt was never actually implemented. It now works as advertised.

  • Couldn’t think of a good reason for require to be a decorator and a function, and the function is more versatile in terms of where it may be used, so the decorator has been removed.

  • As things currently stand with the execution model, the depends decorator doesn’t make a lot of sense: instead, it’s safest/best to simply make “meta” commands that just call whatever chain of “real” commands you need performed for a given overarching task.

    For example, instead of having command A say that it “depends on” command B, create a command C which calls A and B in the right order, e.g.:

    def build():
        local('make clean all')
    def upload():
        put('app.tgz', '/tmp/app.tgz')
        run('tar xzf /tmp/app.tgz')
    def symlink():
        run('ln -s /srv/media/photos /var/www/app/photos')
    def deploy():


    The execution model is still subject to change as Fabric evolves. Please don’t hesitate to email the list or the developers if you have a use case that needs something Fabric doesn’t provide right now!

  • Removed the old fab shell functionality, since the move to “just Python” should make vanilla python/ipython usage of Fabric much easier.

    • We may add it back in later as a convenient shortcut to what basically amounts to running ipython and performing a handful of from import bar calls.
  • The undocumented fab_quiet option has been replaced by a much more granular set of output controls. For more info, see Managing output.

Changes from alpha 1 to alpha 2

The below list was generated by running git shortlog 0.9a1..0.9a2 and then manually sifting through and editing the resulting commit messages. This will probably occur for the rest of the alphas and betas; we hope to use Sphinx-specific methods of documenting changes once the final release is out the door.

  • Various minor tweaks to the (still in-progress) documentation, including one thanks to Curt Micol.
  • Added a number of TODO items based on user feedback (thanks!)
  • Host information now available in granular form (user, host, port) in the env dict, alongside the full user@host:port host string.
  • Parsing of host strings is now more lenient when examining the username (e.g. hyphens.)
  • User/host info no longer cleared out between commands.
  • Tweaked to use find_packages. Thanks to Pat McNerthney.
  • Added ‘capture’ argument to local to allow local interactive tasks.
  • Reversed default value of local‘s show_stderr kwarg; local stderr now prints by default instead of being hidden by default.
  • Various internal fabfile tweaks.

Changes from alpha 2 to alpha 3

  • Lots of updates to the documentation and TODO
  • Added contrib.files with a handful of file-centric subroutines
  • Added contrib.console for console UI stuff (so far, just confirm)
  • Reworked config file mechanisms a bit, added CLI flag for setting it.
  • Output controls (including CLI args, documentation) have been added
  • Test coverage tweaked and grown a small amount (thanks in part to Peter Ellis)
  • Roles overhauled/fixed (more like hosts now)
  • Changed --list linewrap behavior to truncate instead.
  • Make private key passphrase prompting more obvious to users.
  • Add pty option to sudo. Thanks to José Muanis for the tip-off re: get_pty()
  • Add CLI argument for setting the shell used in commands (thanks to Steve Steiner)
  • Only load host keys when env.reject_unknown_keys is True. Thanks to Pat McNerthney.
  • And many, many additional bugfixes and behavioral tweaks too small to merit cluttering up this list! Thanks as always to everyone who contributed bugfixes, feedback and/or patches.

Changes from alpha 3 to beta 1

This is closer to being a straight dump of the Git changelog than the previous sections; apologies for the overall change in tense.

  • Add autodocs for fabric.contrib.console.
  • Minor cleanup to package init and
  • Handle exceptions with strerror attributes that are None instead of strings.
  • contrib.files.append may now take a list of strings if desired.
  • Straighten out how prompt() deals with trailing whitespace
  • Add ‘cd’ context manager.
  • Update upload_template to correctly handle backing up target directories.
  • upload_template() can now use Jinja2 if it’s installed and user asks for it.
  • Handle case where remote host SSH key doesn’t match known_hosts.
  • Fix race condition in run/sudo.
  • Start fledgling FAQ; extended pty option to run(); related doc tweaks.
  • Bring local() in line with run()/sudo() in terms of .failed attribute.
  • Add dollar-sign backslash escaping to run/sudo.
  • Add FAQ question re: backgrounding processes.
  • Extend some of put()’s niceties to get(), plus docstring/comment updates
  • Add debug output of chosen fabfile for troubleshooting fabfile discovery.
  • Fix Python path bug which sometimes caused Fabric’s internal fabfile to pre-empt user’s fabfile during load phase.
  • Gracefully handle “display” for tasks with no docstring.
  • Fix edge case that comes up during some auth/prompt situations.
  • Handle carriage returns in output_thread correctly. Thanks to Brian Rosner.

Changes from beta 1 to release candidate 1

As with the previous changelog, this is also mostly a dump of the Git log. We promise that future changelogs will be more verbose :)

  • Near-total overhaul and expansion of documentation (this is the big one!) Other mentions of documentation in this list are items deserving their own mention, e.g. FAQ updates.
  • Add FAQ question re: passphrase/password prompt
  • Vendorized Paramiko: it is now included in our distribution and is no longer an external dependency, at least until upstream fixes a nasty 1.7.5 bug.
  • Fix #34: switch upload_template to use mkstemp (also removes Python 2.5.2+ dependency – now works on 2.5.0 and up)
  • Fix #62 by escaping backticks.
  • Replace “ls” with “test” in exists()
  • Fixes #50. Thanks to Alex Koshelev for the patch.
  • local‘s return value now exhibits .return_code.
  • Abort on bad role names instead of blowing up.
  • Turn off DeprecationWarning when importing paramiko.
  • Attempted fix re #32 (dropped output)
  • Update role/host initialization logic (was missing some edge cases)
  • Add note to install docs re: PyCrypto on win32.
  • Add FAQ item re: changing
  • Rest of TODO migrated to tickets.
  • fab test (when in source tree) now uses doctests.
  • Add note to compatibility page re: fab_quiet.
  • Update local() to honor

Changes from release candidate 1 to final release

  • Fixed the sed docstring to accurately reflect which sed options it uses.
  • Various changes to internal fabfile, version mechanisms, and other non-user-facing things.