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We are happy to announce the first release candidate of opam 2.4.0. You can view the full list of changes in the release note.

This version is a release candidate, we invite users to test it to spot previously unnoticed bugs as we head towards the final release.

Try it!

The upgrade instructions are unchanged:

1. Either from binaries: run

For Unix systems

bash -c "sh <(curl -fsSL https://opam.ocaml.org/install.sh) --version 2.4.0~rc1"

or from PowerShell for Windows systems

Invoke-Expression "& { $(Invoke-RestMethod https://opam.ocaml.org/install.ps1) } -Version 2.4.0~rc1"

or download manually from the Github "Releases" page to your PATH.

1. Or from source, manually: see the instructions in the README.

You should then run:

opam init --reinit -ni

Changes

• Fix switch creation with pre-release compilers: It was a regression in opam switch create <version> when all compilers of that version are flagged with avoid-version (#6563)
• Performance improvement: ignore VCS directories of non-VCS repositories during opam update (#6560)
• Do not remove the generated patch file during updates when debug-mode is on (#6575)

Release script

• Update some of the platforms the prebuilt binaries are built on to Alpine 2.21, FreeBSD 14.3, OpenBSD 7.7 and NetBSD 10.1 (#6510)

Build changes

• Use coreutils' sha512sum instead of perl's shasum utility when using ./configure --with-cygwin-setup (#6557)
• Upgrade the download-if-missing dependencies to dune 3.19.1, opam-file-format 2.2.0, spdx_licenses 1.4.0 and patch 3.0.0 (#6580)

API changes are also denoted in the release note linked above. This release also includes a couple of improvement and extensions to our testsuite.

Please report any issues to the bug-tracker.

Happy hacking!