checking whether clang++ accepts -g... yes
checking whether g++ accepts -static-libstdc++ -static-libgcc... no
checking for gnatbind... no
checking for gnatmake... no
Press ENTER or type command to continue
checking whether compiler driver understands Ada... no
checking how to compare bootstrapped objects... cmp --ignore-initial=16 $$f1 $$f2
Press ENTER or type command to continue
checking for objdir... .libs
checking for the correct version of gmp.h... yes
checking for the correct version of mpfr.h... yes
checking for the correct version of mpc.h... yes
checking for the correct version of the gmp/mpfr/mpc libraries... yes
checking for version 0.10 of ISL... no
checking for version 0.11 of ISL... no
checking for version 0.12 of ISL... no
configure: error: Unable to find a usable ISL. See config.log for details.
Some background here, I’ve been trying to get the toolchain for my mechanical keyboard set up but for some reason when I was using homebrew I could never get the avr-gcc installed due to a failed isl dependency. No matter what I read and tried I couldn’t get the make script to use the right isl version. I installed and uninstalled isl lord alone knows how many times. I installed and uninstalled the right version of isl012 but couldn’t link the headers correctly. Even the last resort of a symbolic link in my opt folder did nothing.
I have now fixed it.
All you need to do is:
$brew edit avr-gcc
Change the two lines depends_on 'isl' and "__with-isl=#{Formula["isl"].opt_prefix}" to isl012 and you’re good to go.
$brew install avr-gcc
It *should* install the dependency for you and have the bonus of not making your other build chains break due to rolling back. No more failing out on an implicit repository head too far ahead of the make file. I wish there was a way of switching to a previous stable version in homebrew without having to tap formulas using the git switch trigger in a one liner as standard. Something like $brew switch isl 012 would be good but for some reason only some repos support that syntax, postgresql for example.
Seriously, fuck you computer.