Thanks for the report. Looks like the problem is:
:info:configure ERROR at //BUILD.gn:968:7: Script returned non-zero exit code.
:info:configure exec_script("gn/checkpath.py",
:info:configure ^----------
:info:configure Current dir: /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_Aseprite/Aseprite/work/skia/out/Release/
:info:configure Command: python /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_graphics_Aseprite/Aseprite/work/skia/gn/checkpath.py ../../third_party/externals/libgifcodec/libgifcodec.gni
:info:configure Returned 127.
127 means "command not found". It's trying to run python which Apple used to include with macOS but removed in macOS 12.3. I need to update the port to use a MacPorts python instead. (The port already uses a MacPorts python 3, but there used to be parts of the build system that required python 2 and therefore it used the python 2 provided by macOS. I need to check if we can now use python 3 for everything or whether we still need to bring in a python 2.)
I think this was previously reported in #64895 but there was not enough information provided in that ticket to determine what the problem was.
