pluginhandler: do not search installdir or stagedir for dependencies

[cjp256]

The search paths already include primedir which has all of the primed
and staged files at this point. The installdir and stagedir may
contain files that are not shipped in the final snap, so limit search
to primedir as it should be fully populated.

• Replace _handle_dependencies() with a simpler _warn_missing_dependencies()
  and _calculate_dependency_paths() called from _handle_elf().

• Add a couple useful debug prints.

• Add two tests to cover the case where the dependency is found, and
  another where the dependency is missing. For the latter, the lib is
  removed using stage configuration.

This last test would have previously failed, because the dependency
was found in installdir, and ignored by the missing dependency resolver.

Signed-off-by: Chris Patterson chris.patterson@canonical.com

• Have you followed the guidelines for contributing?
• Have you signed the CLA?
• Have you successfully run ./runtests.sh static?
• Have you successfully run ./runtests.sh tests/unit?

---

[cjp256]

This is the starter fix, but I think we should take it further and eliminate use of _find_directory(). I don't think we should be attempting to (re)-search for dependencies.

If we should in fact be re-searching installdir and stagedir for dependencies that were scuttled along the way, perhaps we should move that logic into MissingDependencyResolver..? I'll hold on this pending further discussion.

[cjp256]

@sergiusens just to confirm - we did agree that this check should simply be moved into MissingDependencyResolver?

What do you think about a message like:

This part is missing libraries that cannot be satisfied with the currently primed files. If this is not intended, ensure that these files are not filtered out using the filesets, stage, or prime keywords. Missing libraries include:

• libfoo.so.1, found at parts/foo/install/usr/lib/libfoo.so.1
• libbar.so.1, found at stage/bar/usr/lib/libfoobar.so.1

And my thought would be to filter those files out from the stage-package list, since they were already built/installed/staged.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@16b73e4). Click here to learn what that means.
The diff coverage is 100%.

@@            Coverage Diff            @@
##             master    #2942   +/-   ##
=========================================
  Coverage          ?   88.14%           
=========================================
  Files             ?      229           
  Lines             ?    16589           
  Branches          ?     2564           
=========================================
  Hits              ?    14622           
  Misses            ?     1430           
  Partials          ?      537

Impacted Files	Coverage Δ
snapcraft/internal/build_providers/_lxd/_lxd.py	21.92% <ø> (ø)
.../internal/build_providers/_multipass/_multipass.py	84.61% <ø> (ø)
...apcraft/internal/build_providers/_base_provider.py	84.84% <100%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 16b73e4...5ddebf7. Read the comment docs.