| Subject: | Module::Build remembers that YAML wasn't installed |
Module::Build recommends YAML rather than requiring it. This is fine, one thinks... "I'll install YAML later".
But no! Module::Build remembers the fact that you didn't have YAML installed, by writing this information to Module::Build::Config.pm, where it subsequently looks for it during future builds. If you install YAML afterwards, Module::Build won't use it.
This was causing ./Build dist (distmeta) to fail (for another module that uses Module::Build), and was puzzling me. I fixed the problem by doing a forced install of Module::Build.
I would recommend one of the following:
1. Change Module::Build to check for YAML.pm at run time (preferred).
2. Make YAML into a requires dependency.
3. Change the documentation (pod and INSTALL) to recommend installing YAML first.