Template::Mustache fails to install/recognize dependencies

[dmaestro]

Using zef to install Template::Mustache (a dependency of p6doc) fails tests, reporting missing dependencies which have been downloaded and built, but not yet installed. Using a fresh install on linux, perl6 2018.12.

doug@ender:~$ zef install --install-to=/var/local/test/share/perl6/site URI Template::Mustache
===> Searching for: URI, Template::Mustache
===> Testing: Template::Mustache:ver<1.0.1>:auth<github:softmoth>
# Reading spec files from 't/specs'
# - t/specs/comments.json: 11
# - t/specs/delimiters.json: 14
# - t/specs/interpolation.json: 31
# - t/specs/inverted.json: 21
# - t/specs/partials.json: 11
# - t/specs/sections.json: 26
# - t/specs/~lambdas.json: 10
# Reading spec files from 't/specs'
# - t/specs/comments.json: 11
# - t/specs/delimiters.json: 14
# - t/specs/interpolation.json: 31
# - t/specs/inverted.json: 21
# - t/specs/partials.json: 11
# - t/specs/sections.json: 26
# - t/specs/~lambdas.json: 10
===SORRY!===
Could not find URI at line 70 in:
    /home/doug/.zef/store/p6-Template-Mustache.git/d84fdf303480622805de119024e930c05c9fd6d2/lib
    /home/doug/.zef/store/p6-Template-Mustache.git/d84fdf303480622805de119024e930c05c9fd6d2
    /home/doug/.perl6/lib
    /home/doug/.perl6
    /var/local/test/share/perl6/site
    /var/local/test/share/perl6/vendor
    /var/local/test/share/perl6
    CompUnit::Repository::AbsolutePath<73193568>
    CompUnit::Repository::NQP<47742528>
    CompUnit::Repository::Perl5<47742568>
===> Testing [FAIL]: Template::Mustache:ver<1.0.1>:auth<github:softmoth>
Aborting due to test failure: Template::Mustache:ver<1.0.1>:auth<github:softmoth> (use --force-test to override)

[softmoth]

Thanks for the bug report. Are you still seeing this problem? This module doesn't reference URI anywhere, and I'm not sure where that's coming from.

[dmaestro]

Hmm, looks like that's the case. Wonder if an upstream dependency is doesn't declare it. Since Rakudo* has URI included, a lot of folks won't see this. But I was starting a fresh, build-my-own installation.
I may be able to investigate further next week.

[finanalyst]

I think that the URI dependency is not in Template::Mustache, but in another module that uses T::M. You mention p6doc, so that might be Pod::To::HTML, which does, I think, use URI because POD6 needs to be able to define placements.