[new release] ocaml-protoc-plugin (3 packages) (6.2.0)

[andersfugmann]

Plugin for protoc protobuf compiler to generate ocaml definitions from a .proto file

• Project page: https://github.com/andersfugmann/ocaml-protoc-plugin
• Documentation: https://andersfugmann.github.io/ocaml-protoc-plugin/

CHANGES:

• Fix potential nameclash for messages defining extensions
• Resolve compilation warning on deprecated fields enclosed in a oneof
• Improve how comments are copied to generated code
• Add flag 'singleton_oneof_as_option' to map single field
  onofs to option type (default on). Set to 'false' to keep old
  behaviour.
• Improve copying of comments from .proto files into ocaml code using
  omd to parse markdown
• Fix problem with deserializing large singed integers (OCaml Protoc Plugin incorretly parses Int64.min_int in sint64 field andersfugmann/ocaml-protoc-plugin#45)

[andersfugmann]

The tests are only expected to run on Linux/Mac platforms where the protoc command can be found in path. Is there a way to instruct CI not to run tests on windows?

[jmid]

Thanks!

I'm puzzled by these new conf-protoc* package versions.

• First off, they are specifying src and url without using the given src tar-ball.
• Secondly, they don't seem to add any features to the current latest versions (so why publish new ones? 🤔). Rather they miss some of the updates that have since been made to the existing ones on the repo: 😬

opam-repository$ git grlog packages/conf-protoc/conf-protoc.4.4.0/opam

• 7f0b734 - (4 months ago) Switch from os-distribution = "fedora" to os-family = "fedora"
• 4d05149 - (1 year, 6 months ago) Skip ci on oraclelinux-9 for conf-protoc since the package is not available by default
• 348a169 - (2 years, 1 month ago) Add support for OpenSUSE Tumbleweed
• e111c6f - (2 years, 6 months ago) Packages conf-protoc.4.4.0 and ocaml-protoc-plugin.4.4.0

opam-repository$ git grlog packages/conf-protoc-dev/conf-protoc-dev.1.0.0/opam

• 7f0b734 - (4 months ago) Switch from os-distribution = "fedora" to os-family = "fedora"
• 1421b09 - (1 year, 4 months ago) Remove source reference from conf-protoc-dev and reset to version 1.0.0

Finally, you can disable a package on Windows with available: os != "win32".
If it is just runtest that needs disabling, I believe it can be guarded with { os != "win32 }.

[andersfugmann]

My bad. I did not want to publish new versions of the ‘conf-protoc’ package. Ill remove these and inhibit tests on windows.

[andersfugmann]

Hmm. Adding & os != "win32" to the test command in opam file did not seem to do the trick.

[jmid]

Hmm. Adding & os != "win32" to the test command in opam file did not seem to do the trick.

The failure comes when attempting to run protoc under the conf-protoc package installation. Currently it doesn't have a depext and hence fails executing protoc (after having installed no external package):

 #=== ERROR while compiling conf-protoc.4.4.0 ==================================#
  "protoc": command not found.

This is thus to be expected.

If we want to extend conf-protoc (probably in a separate PR) I can see Cygwin packages here, but no MinGW packages for protobuf: https://cygwin.com/packages/package_list.html
MSys2 on the other hand has a (64-bit) MinGW package: https://packages.msys2.org/packages/mingw-w64-x86_64-protobuf

As for this PR, I can see lower bounds failures for the omd dependency, which would be good to address 🙂

Edit - I forgot: Thanks for adding x-maintenance-intent 🙏

[andersfugmann]

I've addressed the lower bound for omd. I'll see if I can find a way to test the conf-protoc packages on windows later, but I dont think it should block merging of the packages here. wdyt?

[jmid]

I agree, conf-protoc's Windows failure shouldn't block this one.

CI summary:

• When running --with-test (and exploring lower bounds) this fails on alpine-3.21-ocaml-5.3, archlinux-ocaml-5.3, opensuse-15.6-ocaml-5.3, opensuse-tumbleweed-ocaml-5.3 with #error "C++ versions less than C++14 are not supported." and #error "C++ versions less than C++17 are not supported."
• uunf.16.0.0 fails to build on 4.14 under flambda, which is a known issue 4.14.2+flambda: stack overflow while compiling uunf 16.0.0 ocaml#14166
• two FreeBSD workflow time out
• Windows fails installing conf-protoc as it isn't currently supported

I'm unsure whether anything should be done about the former, failing C++ compiler version check during --with-test - and what is causing it. Older Debian/Ubuntu is using older gcc's, yet pass the test and so does Fedora-42 which IIUC has moved to gcc-15 🤔

[andersfugmann]

The errors come from compiling protobuf test stubs, related to json tests.

# /usr/include/absl/base/policy_checks.h:79:2: error: #error "C++ versions less than C++14 are not supported."
2025-08-30 22:50.31: >>> 
# /usr/include/google/protobuf/port_def.inc:210:15: error: static assertion failed: Protobuf only supports C++14 and newer.

Why the package systems does not ensure availability of a usable compiler is beyond me, and I dont think we should fix this. We can add additional x-ci-accept-failures (that already exclude homebrew, because it also does not provide C++14.