If one has moved /usr/local to a separate file system and symlink'ed it to it's original location (e.g.: /usr/ports - > /u1/usr-local ), then during install the commands:
/bin/mkdir -p /usr/ports/devel/ruby-gems/work/stage/usr/local/lib/ruby/gems/2.6
cd /usr/ports/devel/ruby-gems/work/rubygems-3.0.6/ && /usr/bin/env DONT_USE_BUNDLER_FOR_GEMDEPS=true G
EM_HOME=/usr/ports/devel/ruby-gems/work/stage/usr/local/lib/ruby/gems/2.6 /usr/local/bin/ruby26 setup.
rb --destdir=/usr/ports/devel/ruby-gems/work/stage --no-regenerate-binstubs --no-ri --no-rdoc
causes the creation of two trees in ./stage:
./stage/usr/local... [everything else]
Only the script gem26 appears in the path ./u1/usr-local/.., but that's sufficient for the install to fail with:
pkg-static: Unable to access file /usr/ports/devel/ruby-gems/work/stage/usr/local/bin/gem26:No such fi
le or directory
My work-around was to "make" "mv u1/usr-local/bin/gem26 usr/local/bin/" "make install"
I believe this is a bug in the ruby script 'setup,' but I have never learned ruby.