Bug #21092: error building ruby 3.4.1 on cygwin/msys2

• Status: Closed
• Assignee: hsbt (Hiroshi SHIBATA)
• Target version: -
• Backport: 3.1: REQUIRED, 3.2: DONE, 3.3: REQUIRED, 3.4: DONE

[jeremyd2019 (Jeremy Drake)]

While building from the release tarball ruby-3.4.1.tar.xz on cygwin (also confirmed in snapshot-master.tar.gz from Jan 27, 2025), I get the following error:

../ruby-3.4.1/ext/extmk.rb:279:in 'Array#-': no implicit conversion of nil into Array (TypeError)
from ../ruby-3.4.1/ext/extmk.rb:279:in 'Object#extmake'
from ../ruby-3.4.1/ext/extmk.rb:659:in 'block in '
from ../ruby-3.4.1/ext/extmk.rb:653:in 'Array#each'
from ../ruby-3.4.1/ext/extmk.rb:653:in ''

I have tracked this down to happening when an ext writes a dummy makefile. In this case, that ext is .bundle/gems/syslog-0.2.0.
See https://github.com/ruby/syslog/pull/16 for fixing why it is writing a dummy makefile to begin with, but still, it seems like extmk.rb should handle this case gracefully rather than breaking the build.

[jeremyd2019 (Jeremy Drake)]

• Description updated (diff)

[hsbt (Hiroshi SHIBATA)]

• Status changed from Open to Assigned
• Assignee set to hsbt (Hiroshi SHIBATA)

I could reproduce this.

https://github.com/ruby/ruby/actions/runs/13001828367/job/36261824250?pr=12649

[hsbt (Hiroshi SHIBATA)]

• Subject changed from error building ruby 3.4.1 on cygwin to error building ruby 3.4.1 on cygwin/msys2

[nobu (Nobuyoshi Nakada)]

I cannot reproduce that error at all, with ruby-3.4.1.

[nobu (Nobuyoshi Nakada)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN to 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED

nobu (Nobuyoshi Nakada) wrote in #note-4:

I cannot reproduce that error at all, with ruby-3.4.1.

This was because I failed to get msys to pretend to be cygwin, and it reproduced by simply trying on cygwin.
MSys is mysterious.

[nobu (Nobuyoshi Nakada)]

• Status changed from Assigned to Closed

Applied in changeset git|2b6fc9ea7212543a1be26768403f59c7a759b5ea.

---

[Bug #21092] Fallback variables after execonf has done

When reading from a dummy makefile, the global variables initialized
in init_mkmf may not be overridden.

[k0kubun (Takashi Kokubun)]

• Backport changed from 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED to 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED, 3.4: DONE

ruby_3_4 2ee25f7b47a30b7515cdb4da341d28931d8b5810 merged revision(s) 2b6fc9ea7212543a1be26768403f59c7a759b5ea.

[hsbt (Hiroshi SHIBATA)]

• Backport changed from 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED, 3.4: DONE to 3.1: REQUIRED, 3.2: DONE, 3.3: REQUIRED, 3.4: DONE