Wrong Compiler Selected When Building With Make

[Carltoffel]

This line

stdlib/Makefile.manual

Line 3 in 9f1aa24

FC ?= gfortran

should set FC to gfortran, if no other compiler is defined. But on some (don't know on how many) systems FC is preset to f77. Since I don't have f77 (and I doubt it would be able to compile stdlib) the build process fails.
Is there anything we can do about this issue? Maybe check the value of FC if it is set to such a default value and print a error/warning message?
The current warning is a little bit misleading:
f77: No such file or directory

Testet on:
Arch Linux, GNU Make 4.3 built for x86_64-pc-linux-gnu
Fedora 35, GNU Make 4.3 built for x86_64-redhat-linux-gnu

[awvwgk]

On Arch Linux FC is not set for me. Even when running inside makepkg there is no value in the FC environment variable predefined. Usually CMake is picking up f95 from /usr/bin which is equivalent to gfortran on most platforms.

[Carltoffel]

In my shell FC is not set, too. Where else could f77 come from? If it would select f95 it would work, but this doesn't happen.

[ivan-pi]

Closing due to #657 (Remove support for manual make builds).