Failed to fetch libgcc8: incompatible OS X version

[prtouatisid (S. Touati)]

Hello,
I am trying to solve this problem since many weeks, without success. I did port selfupdate ; port upgrade outdated. The error message is:

--->  Attempting to fetch libgcc8-8.3.0_5.darwin_19.x86_64.tbz2 from http://nue.de.packages.macports.org/libgcc8
--->  Attempting to fetch libgcc8-8.3.0_5.darwin_19.x86_64.tbz2 from http://lil.fr.packages.macports.org/libgcc8
--->  Attempting to fetch libgcc8-8.3.0_5.darwin_19.x86_64.tbz2 from https://packages.macports.org/libgcc8
--->  Fetching distfiles for libgcc8
Error: gcc8 8.3.0 is (currently) not supported on Darwin 19
Error: See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90835 for more details
Error: Until the issue is addressed in Xcode, please instead install gcc9 / libgcc9
Error: Failed to fetch libgcc8: incompatible OS X version
Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_gcc8/libgcc8/main.log for details.
Error: Problem while installing libgcc8
Error: Follow https://guide.macports.org/#project.tickets to report a bug.

My OS versions is macOS Catalina v10.15.1
I installed gcc9 and , and uninstalled gcc8 and libgcc8, but the problem with gcc8 still appears when I execute port upgrade outdated. I also reinstalled xcode, and the command line tools, without success.
Maybe I am doing something wrong. I enclose the log file.
Any help ?

Thanks

[prtouatisid (S. Touati)]

log file /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_gcc8/libgcc8/main.log

[jmroot (Joshua Root)]

You must have something installed that depends on libgcc8. Try running this command: port echo installed and depends:gcc8

[kencu (Ken)]

gcc8/libgcc8 do install on 10.15.

closing as no further actionable information.