The problem reported 2020-06-18 was due to the way plugins were then, e.
g. upstream commit 93d3f7f2, enabled by default. Meanwhile, this way was
modified.
Thus, the current PKGBUILD builds current upstream commits, e. g.
e68d0c69, just fine again.
At least many of the rather important features, which the package
currently lacks, seem very buggy.
E. g. enabling HEIF doesn't work with the recommended additional plugin
or downloading the plugins as submodules fails, even when the
recommendation of comment 2021-01-24 is considered.
All in all, "unaddressed build issues" do not exist, and any further
discussion should take place in the comment section, IMO.