package obuilder-spec

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Build specification format


Dune Dependency






  • Updates to address rsync and sandbox issues. (@mtelvers #139, reviewed by @tmcgilchrist and @MisterDA)

  • Add an obuilder clean command to clean all build results. (@MisterDA #140, reviewed by @tmcgilchrist)

  • Make rsync-mode mandatory when using rsync store. (@tmcgilchrist #132, reviewed by @kit-ty-kate and @MisterDA)


  • Add --fuse-path to allow selection of the path redirected by FUSE (@mtelvers #128, reviewed by @MisterDA )

  • Pre-requisites for Windows support using docker for Windows (@MisterDA #116, reviewed by @tmcgilchrist)

  • Additional tests and prerequistes for Windows support (@MisterDA #130, reviewed by @tmcgilchrist)

  • Add support for Docker/Windows spec (@MisterDA #117, reviewed by @tmcgilchrist)

  • Depend on Lwt.5.6.1 for bugfixes (@MisterDA #108, reviewed by @tmcgilchrist)

  • Add macOS support (@patricoferris #87, reviewed by @tmcgilchrist @talex5 @kit-ty-kate)

  • Enable macOS tests only on macOS (@MisterDA #126, reviewed by @tmcgilchrist)

  • Dune 3.0 generates empty intf for executables (@MisterDA #111, reviewed by @talex5)

  • Fix warnings and CI failure (@MisterDA #110, reviewed by @talex5)

  • Expose store root and cmdliner term with non-required store (@MisterDA #119, reviewed by @tmcgilchrist)

  • Expose Rsync_store module (@MisterDA #114, reviewed by @talex5)

  • Rsync hard-links to save space (@art-w #102, reviewed by @patricoferris)


  • Use GNU tar format instead of UStar for copy operations (@TheLortex #82, reviewed @dra27). This enables copying from sources containing long file names (>100 characters).

  • Add support for secrets (@TheLortex #63, reviewed by @talex5). The obuilder spec's run command supports a new secrets fields, which allows to temporarily mount secret files in an user-specified location. The sandbox build context has an additional secrets parameter to provide values for the requested keys.

  • Limit permissions on temporary directories (@talex5 #67)

  • Check Linux kernel version support for btrfs (@kit-ty-kate #68)

  • Generalise obuilder sandbox, removing runc/linux specific pieces and making the S.SANDBOX interface more general (@patricoferris #58, reviewed by @talex5, @avsm, @MisterDA)

  • Convert --fast-sync back to a flag (@talex5 #72)

  • Support Fmt.cli and Logs.cli flags. (@MisterDA #74, reviewed by @talex5) For Fmt the new options are --color=always|never|auto For Log the new options are: -v, --verbose Increase verbosity --verbosity=LEVEL (absent=warning) Be more or less verbose. LEVEL must be one of quiet, error, warning, info or debug. Takes over -v.

  • Minor cleanup changes (@talex5 #76)

  • Fix deprecations in Fmt 0.8.10 (@tmcgilchrist #80)

  • Remove travis-ci and replace with Github Actions (@MisterDA #84)

  • Add RSync store backend for obuilder to support macOS builders (@patricoferris #88, reviewed @talex5)

  • Fixes for ZFS tests in CI (@patricoferris #91)


Security fix:

  • resolv.conf file should be mounted read-only.

Other changes:

  • Make Os and Db modules private. Move the env type to Config, as that is used externally.

  • Fix license. It was copy-pasted from OCurrent, and still mentioned that project's lib_ansi library.

  • Require obuilder-spec package to be same version.


  • Add support for nested / multi-stage builds (@talex5 #48 #49). This allows you to use a large build environment to create a binary and then copy that into a smaller runtime environment. It's also useful to get better caching if two things can change independently (e.g. you want to build your software and also a linting tool, and be able to update either without rebuilding the other).

  • Add healthcheck feature (@talex5 #52).

    • Checks that Docker is running.

    • Does a test build using busybox.

  • Clean up left-over runc containers on restart (@talex5 #53). If btrfs crashes and makes the filesystem read-only then after rebooting there will be stale runc directories. New jobs with the same IDs would then fail.

  • Remove dependency on dockerfile (@talex5 #51). This also allows us more control over the formatting (e.g. putting a blank line between stages in multi-stage builds).

  • Record log output from docker pull (@talex5 #46). Otherwise, it's not obvious why we've stopped at a pull step, or what is happening.

  • Improve formatting of OBuilder specs (@talex5 #45).

  • Use seccomp policy to avoid necessary sync operations (@talex5 #44). Sync operations are really slow on btrfs. They're also pointless, since if the computer crashes while we're doing a build then we'll just throw it away and start again anyway. Use a seccomp policy that causes all sync operations to "fail", with errno 0 ("success"). On my machine, this reduces the time to apt-get install -y shared-mime-info from 18.5s to 4.7s. Use --fast-sync to enable to new behaviour (it requires runc 1.0.0-rc92).

  • Use a mutex to avoid concurrent btrfs operations (@talex5 #43). Btrfs deadlocks enough as it is. Don't stress it further by trying to do two things at once.

Internal changes:

  • Improve handling of file redirections (@talex5 #46). Instead of making the caller do all the work of closing the file descriptors safely, add an FD_move_safely mode.

  • Travis tests: ensure apt cache is up-to-date (@talex5 #50).


Initial release.