Originally, the failed test case reported following error:
~~~
Failure: test_gem_exec_gem_uninstall(TestGemCommandsExecCommand):
<""> was expected to include
<"Successfully uninstalled a-2\n">.
/mnt/test/rubygems/test_gem_commands_exec_command.rb:742:in `block in test_gem_exec_gem_uninstall'
739:
740: # assert_empty @ui.error
741: refute_includes @ui.output, "running gem exec with"
=> 742: assert_includes @ui.output, "Successfully uninstalled a-2\n"
743:
744: invoke "--verbose", "gem", "uninstall", "b"
745: assert_includes @ui.output, "Successfully uninstalled b-2\n"
/mnt/lib/rubygems/user_interaction.rb:46:in `use_ui'
/mnt/lib/rubygems/user_interaction.rb:69:in `use_ui'
/mnt/test/rubygems/test_gem_commands_exec_command.rb:726:in `test_gem_exec_gem_uninstall'
~~~
This does not tell much. Empty string is more often good sign, but not
in this case. However, checking error output first helps with
understanding possible issue:
~~~
Failure: test_gem_exec_gem_uninstall(TestGemCommandsExecCommand):
<"ERROR: While executing gem ... (Gem::FilePermissionError)\n" +
" You don't have write permissions for the /builddir/bin directory.\n" +
"\t/mnt/lib/rubygems/uninstaller.rb:213:in `remove_executables'\n" +
... snip ...
/mnt/test/rubygems/test_gem_commands_exec_command.rb:740:in `block in test_gem_exec_gem_uninstall'
737: nil
738: end
739:
=> 740: assert_empty @ui.error
741: refute_includes @ui.output, "running gem exec with"
742: assert_includes @ui.output, "Successfully uninstalled a-2\n"
743:
/mnt/lib/rubygems/user_interaction.rb:46:in `use_ui'
/mnt/lib/rubygems/user_interaction.rb:69:in `use_ui'
/mnt/test/rubygems/test_gem_commands_exec_command.rb:726:in `test_gem_exec_gem_uninstall'
~~~
BTW this issue is caused by operating_system.rb overriding
`Gem.operating_system_defaults` method and explicitly adding `--bindir`
option.
https://github.com/rubygems/rubygems/commit/d98e36bbe7