package obuilder-spec

v0.7.0 2026-05-12

New backends:

• Add an Overlayfs store backend (@mtelvers #180)
• Add a QEMU sandbox backend, enabling Windows, OpenBSD and RISC-V builds (@mtelvers #195, reviewed by @MisterDA, @samoht, and @shonfeder)
• Add an HCS (Host Compute Service) backend for native Windows containers via containerd (@mtelvers #204)

Build, store and runtime fixes:

• Failed builds now correctly return a failure exit status (@mtelvers)
• Fix stale base image cache causing worker crash after pruning (@mtelvers)
• Re-raise exceptions to preserve backtraces and prefer failwith over Lwt.fail_with (@MisterDA)
• Remove unused Os.copy, delete_recursively and win32_unlink (@MisterDA, @shonfeder)

Copy step fixes:

• Fix copy step failure with tar 1.34 and the CVE-2025-45582 patch (@mtelvers #205)
• Also strip ./ segments from destination tar paths (@mtelvers #206)
• Remove synchronous Windows workaround in copy_file (@mtelvers)

Windows fixes:

• Display Windows NTSTATUS exit codes in hex (@MisterDA #197, reviewed by @mtelvers)
• Fix opam pin on Windows (@mtelvers #196, reviewed by @shonfeder)

Base images, CI and toolchain:

• Update base images and workers to opam 2.5, opam 2.4.1, opam 2.3, OCaml 5.4 and OCaml 5.3; add OpenBSD 7.7 support (@mtelvers #198 #201 #202)
• Update GHA scripts: use the latest OCaml 5, switch to setup-ocaml@v3, update runc to 1.1.14 (@MisterDA)
• Update opam image hashes and dependency lower bounds for bug fixes; add an upper bound on tar-unix 3 (@MisterDA, @shonfeder)

v0.6.0 2024-01-31

• Add a Docker backend for Windows and Linux jobs. (@MisterDA #127 #75, reviewed by @talex5 and @tmcgilchrist)
• Add FreeBSD sandbox backend using jail(8) (@dustanddreams #156 #174, reviewed by @tmcgilchrist, @MisterDA, and @mtelvers)
• Add Macos ZFS sandbox (@mtelvers #164, reviewed by @tmcgilchrist)
• Support XFS store (@mtelvers #170, reviewed by @tmcgilchrist)
• Search for bash rather than assume it lies in /bin (@dustanddreams #159, reviewed by @tmcgilchrist)
• Prune builds one at a time up to the limit (@mtelvers #157)
• Specify upper bound on number of items in the store (@mtelvers #158, reviewed by @MisterDA)
• Fix case where BTRFS is not fully allocated (@mtelvers #162)
• Avoid pruning parent cache objects (@mtelvers #176, reviewed by @tmcgilchrist)

v0.5.1 2023-02-17

• 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)

v0.5 2022-11-08

• 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)

v0.4 2022-06-17

• 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)

v0.3 2021-03-16

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.

v0.2 2020-12-30

• 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).

v0.1 2020-10-30

Initial release.