bazel: builds failing for macOS 10.12 through 10.15

[mascguy (Christopher Nielsen)]

This port has been failing to build on 10.12 through 10.15, since May 2021.

The latest failures are the following:

ERROR: /opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_devel_bazel/bazel/work/bazel-4.2.2-dist/third_party/zlib/BUILD:25:19: Compiling third_party/zlib/inffast.c failed: undeclared inclusion(s) in rule '//third_party/zlib:zlib_checked_in':
this rule is missing dependency declarations for the following files included by 'third_party/zlib/inffast.c':
  '/opt/local/libexec/llvm-13/lib/clang/13.0.0/include/stddef.h'
  '/opt/local/libexec/llvm-13/lib/clang/13.0.0/include/__stddef_max_align_t.h'
  '/opt/local/libexec/llvm-13/lib/clang/13.0.0/include/limits.h'
  '/opt/local/libexec/llvm-13/lib/clang/13.0.0/include/stdarg.h'
  '/opt/local/libexec/llvm-13/lib/clang/13.0.0/include/stdint.h'

​https://ports.macports.org/port/bazel/builds/

[cjones051073 (Chris Jones)]

Yeah, I am aware. Unfortunately I no longer have access to < macOS12 at the moment, so was just hoping this update might just help...

bazel is a painful build to work on, but if anyone with these older OSes wants to look please do ?

note though, any port using bazel uses one of the older pinned version ports, so this isn't affecting other builds yet.

[mascguy (Christopher Nielsen)]

Replying to cjones051073:

Yeah, I am aware. Unfortunately I no longer have access to < macOS12 at the moment, so was just hoping this update might just help...

I'm happy to help, but will need some hints/direction as to what might need to change. Thoughts?

[cjones051073 (Chris Jones)]

Getting the bazel build to use a non-Xcode compiler has always been a huge headache. Honestly, I have seen these sorts of errors before but don't really have good suggestions as to exactly what needs to be done to help. The place to start is where in the Portfiles it detects its using macports clang, and attempts to use the BAZEL_USE_CPP_ONLY_TOOLCHAIN=1 option...

[cjones051073 (Chris Jones)]

Actually, now I look again I recall that path isn't used as it didn't work last time I tried...

bazel internally builds (yes, builds, its c++) its own wrapper around the compiler used. So to get it to use a macports compiler I had to patch this. see

​https://github.com/macports/macports-ports/blob/f724e39a14363cc10482135c2410310f2644b07d/devel/bazel/Portfile#L259

as perhaps a better place to start.

but, I warn you again, this is really a rabbit hole of Alice in Wonderland proportions...

[mascguy (Christopher Nielsen)]

Reassigning to Steve, since he's working on fixing bazel per PR:

​15397 - py-tensorflow, bazel: Bugfixes and Updates

[essandess (Steve Smith)]

I don't have access to any of these older macOS versions, am skeptical that upstream even support such builds (see ​https://trac.macports.org/ticket/64442#comment:9, ​https://lists.macports.org/pipermail/macports-dev/2022-July/044443.html), and do not have any time resources to support this issue.

I suggest adding this known failure to the Portfile and moving on.