[MacPorts] #61644: py38-matplotlib fails to compile/install on BigSur with Apple Silicon

[MacPorts]

#61644: py38-matplotlib fails to compile/install on BigSur with Apple Silicon
-----------------------------+--------------------------------------
 Reporter:  Gregory-Gelfond  |      Owner:  (none)
     Type:  defect           |     Status:  new
 Priority:  Normal           |  Milestone:
Component:  ports            |    Version:  2.6.4
 Keywords:  bigsur arm64     |       Port:  py38-matplotlib libgcc10
-----------------------------+--------------------------------------
 Invoking the command `sudo port install py38-matplotlib +cairo
 +ghostscript +latex +tkinter +webagg` fails due to issues with `libgcc10`:

 {{{
 --->  Attempting to fetch libgcc10-10.2.0_3.darwin_20.arm64.tbz2 from
 https://packages.macports.org/libgcc10
 --->  Attempting to fetch libgcc10-10.2.0_3.darwin_20.arm64.tbz2 from
 https://ywg.ca.packages.macports.org/mirror/macports/packages/gcc10/libgcc10
 --->  Attempting to fetch libgcc10-10.2.0_3.darwin_20.arm64.tbz2 from
 https://mse.uk.packages.macports.org/libgcc10
 --->  Fetching distfiles for libgcc10
 Error: gcc10 10.2.0 is not supported on Darwin 20 arm
 Error: Failed to fetch libgcc10: incompatible OS X version
 Error: See
 /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_gcc10/libgcc10/main.log
 for details.
 Error: Follow https://guide.macports.org/#project.tickets to report a bug.
 Error: Processing of port py38-matplotlib failed
 }}}

 I've attached the main.log file for reference.

-- 
Ticket URL: <https://trac.macports.org/ticket/61644>
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