activation error of port gmic

[karo11]

Installation of port gmic delivers during activation an error

--->  Computing dependencies for gmic
--->  Fetching archive for gmic
--->  Attempting to fetch gmic-2.3.2_0.darwin_17.x86_64.tbz2 from http://nue.de.packages.macports.org/gmic
--->  Attempting to fetch gmic-2.3.2_0.darwin_17.x86_64.tbz2 from https://packages.macports.org/gmic
--->  Attempting to fetch gmic-2.3.2_0.darwin_17.x86_64.tbz2 from http://lil.fr.packages.macports.org/gmic
--->  Fetching distfiles for gmic
--->  Attempting to fetch gmic_2.3.2.tar.gz from http://nue.de.distfiles.macports.org/gmic
--->  Verifying checksums for gmic
--->  Extracting gmic
--->  Applying patches to gmic
--->  Configuring gmic
--->  Building gmic
--->  Staging gmic into destroot
--->  Installing gmic @2.3.2_0
Error: unknown target: clean
--->  Computing dependencies for gmic
Error: Couldn't activate gmic 2.3.2_0: can't read "targetname": no such variable
Error: Follow https://guide.macports.org/#project.tickets to report a bug.

Succeeding manual activation works!

Installation with debug flag delivers some add. messages

...
DEBUG: activating file: /opt/local/share/man/fr/man1/gmic.1.gz
DEBUG: activating directory: /opt/local/share/man/man1
DEBUG: activating file: /opt/local/share/man/man1/gmic.1.gz
DEBUG: Executing portactivate::activate_finish
Error: unknown target: load
Error: Failed to load gmic
Error: unknown target: clean
--->  Scanning binaries for linking errors
DEBUG: Ignoring loadcommand containing @executable_path in /opt/local/libexec/ld64/ld-latest
DEBUG: Ignoring loadcommand containing @rpath in /Applications/MacPorts/Qt5/Qt Creator.app/Contents/Frameworks/libCPlusPlus.4.6.1.dylib
DEBUG: Ignoring loadcommand containing @rpath in /Applications/MacPorts/Qt5/Qt Creator.app/Contents/Frameworks/libClangsupport.4.6.1.dylib
...