question about overriding the platforms statement in subports

[Ken Cunningham]

I'm trying to understand why I see this error when trying to install gcc7 on 10.5 PPC, using the PR we are working on in https://github.com/macports/macports-ports/pull/26655 to update the default gcc compiler on older systems to gcc14.

gcc 8, 11, 12, and 13 are not currently enabled for systems < 10.6, as I haven't verified their builds yet.
libgcc8, 11, 12, and 13 install stub ports that install just a README file.

The gcc8 portfile, for example, contains this at the top:

platforms           {darwin >= 10 < 15}

and then this lower down, near the libgcc8 stub port:

platforms {darwin < 15}



I would think that when installing libgcc8 therefore, there would be no issues, however I see this error:

====
$ sudo port -v install gcc7
---> Computing dependencies for gcc7...
libgcc8 is known to fail. Try to install anyway? [y/N]: y
...
libgcc11 is known to fail. Try to install anyway? [y/N]: y
.
libgcc12 is known to fail. Try to install anyway? [y/N]: y
.
libgcc13 is known to fail. Try to install anyway? [y/N]: y

The following dependencies will be installed: 
libgcc10
libgcc11
libgcc12
libgcc13
libgcc7
libgcc8
libgcc9
=====



Why does libgcc8, for example, say it is "known to fail"?

Thanks, Ken