mpich-default @3.4.1_3: seems to be disabled on Leopard -- but installs easily

[kencu (Ken)]

I was getting around to upgrading the ports on some of my older systems, and on my main Leopard workhorse, mpich-default would not upgrade.

It said it was not supported on Leopard, which came as a surprise to me, as it installed without any trouble at all a few weeks ago, and the version has not changed.

Things in the mpich-* world have become rather impressively more complicated since the last time I looked, with the port trying to do a lot of figuring out what compilers do and don't work on which systems. That is such a moving target it will be hard to keep that logic current. For example, it says that gcc9 won't build on 10.7, or that clang-11 won't build on 10.6, but they do, AFAIK.

Anyway, after a fair amount of trying to figure out what is going on. I (think I) found the switch to flip that was disabing mpich-default on Leopard, and with this little patch:

$ diff -u Portfile `port file mpich-default`
--- Portfile	2021-06-05 19:31:01.000000000 -0700
+++ /opt/local/var/macports/sources/rsync.macports.org/macports/release/tarballs/ports/science/mpich/Portfile	2021-06-05 19:12:23.000000000 -0700
@@ -82,7 +82,7 @@
 dict set clist gcc7 {macports-gcc-7}
 
 # Only enable default (gcc), and Xcode clang, for MacOS 10.7 and later
-if { ${os.major} >= 11 } {
+if { ${os.major} >= 1 } {
     dict set clist default {}
     dict set clist clang   {clang}
 } else {

all was well in the world once again. mpich-default builds through with the lowly, 15 year old /usr/bin/gcc-4.2 on Leopard, so it's compiler requirements would appear to be quite modest, in the end.

$ port -v installed mpich-default
The following ports are currently installed:
  mpich-default @3.4.1_1+gcc7 requested_variants='+gcc7' platform='darwin 9' archs='i386' date='2021-03-17T14:22:49-0700'
  mpich-default @3.4.2_0+gcc7 (active) requested_variants='' platform='darwin 9' archs='i386' date='2021-06-05T19:28:20-0700'