Initialize terminfo.bzl linkopts to None

[jonmeow]

Summary

The underlying issue here is that line 125 checks if linkopts was assigned (by line 120) but it's not initialized, so that becomes a crash. This was noticed by someone trying to use Docker, so no terminfo library installed.

[jonmeow]

The underlying issue here is that line 125 checks if linkopts was assigned (by line 120) but it's not initialized, so that becomes a crash. This was noticed by someone trying to use Docker, so no terminfo library installed.

Sorry if I'm doing something wrong here, I'm new to phabricator.

[GMNGeoffrey]

LGTM. Thanks for the fix. Can you add the explanation to the description? Also, do you need me to land this for you? If so, do you want it committed with the author information from this commit "jonmeow <[e-mail]>"?

[jonmeow]

Trying to modify the commit.

[jonmeow]

I've moved my explanation into the description, and I think the commit reflects it now. I don't have LLVM commit access, so I think I do need you to land it. I'm fine with that attribution (if you want a working email, "jonmeow <[e-mail]>" would be fine too).

[jonmeow]

Thanks!

utils/bazel/terminfo.bzl

else:
 
         # Get the source file we use to detect successful linking of terminfo.
         source = repository_ctx.path(repository_ctx.attr._terminfo_test_source)
 
         # Collect the candidate linkopts and wrap them into a list. Ideally,
         # these would be provided as lists, but Bazel doesn't currently
         # support that. See: https://github.com/bazelbuild/bazel/issues/12178
         linkopts_candidates = [[x] for x in repository_ctx.attr.candidate_system_linkopts]
+        linkopts = None
 
         # For each candidate, try to use it to link our test source file.
         for linkopts_candidate in linkopts_candidates:
             if _try_link(repository_ctx, cc, source, linkopts_candidate):
                 linkopts = linkopts_candidate
                 break
 
         # If we never found a viable linkopts candidate, either error or disable