falcon @0.9.6.8_1: after successful build, falcon fails with error dyld: Library not loaded: libfalcon_engine.1.dylib

[dbevans (David B. Evans)]

rev-upgrade gives some more detail:

$ sudo port -v rev-upgrade
--->  Scanning binaries for linking errors
Could not open libfalcon_engine.1.dylib: Error opening or reading file (referenced from /opt/local/bin/falcon)
libfalcon_engine.1.dylib seems to be referenced using a relative path. This may be a problem with its canonical library name and require the use of install_name_tool(1) to fix.
--->  Found 6 broken files, matching files to ports      
--->  Found 1 broken port:
     falcon @0.9.6.8 
         /opt/local/bin/falcon
         /opt/local/bin/faldisass
         /opt/local/bin/falpack
         /opt/local/bin/falrun
         /opt/local/bin/faltest
         /opt/local/lib/falcon/testsuite_fm.dylib

Indicating that all the falcon binaries are linked against relative path libfalcon_engine.1.dylib rather than the full ${prefix}/lib/libfalcon_engine.1.dylib as installed.

This is confirmed by otool as follows:

$ otool -L /opt/local/bin/falcon
/opt/local/bin/falcon:
	libfalcon_engine.1.dylib (compatibility version 1.0.0, current version 1.22.2)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.200.5)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 400.9.4)

[nerdling (Jeremy Lavergne)]

In 345b8cea9f7deb48bfc95167c75e61c7d39594b0/macports-ports (master):

falcon: fix rpath so linked library is found once post-install

Fixes #57993