I just updated my Mac Book Pro to El Capitan (10.11.4) and gcc 5.2 broke, so I installed gcc 5.3.0 using homebrew but the new compiler is not linked to /usr/local/bin/gcc. Instead it's linked to /usr/local/bin/gcc-5. Likewise, all the related commands (g++, gcc-ar, gcc-ranlib, ...) have now the '-5' appended whereas the plain gcc family w/o '-5' is still linked to 5.2.
Is there a way to force homebrew to link to plain gcc?
#!/usr/bin/perl
# relink_gcc unlinks the old gcc and links the current version
#
# SYNOPSIS:
# cd /usr/local/bin
# relink_gcc
#
# DESCRIPTION:
# Homebrew installs gcc version N.X as gcc-N. All other components
# of the Gnu Compiler Collection are installed with the '-N' suffix.
# E.g. g++-N, c++-N, ... However, I prefer to have the names w/o
# the '-N' suffix so I can use the same Makefiles on different
# computers. This program changes the links from the plain gcc
# (and its family) to point to the most recent gcc version.
# Because 'darwin' also changes version, the program changes the
# version of programs with 'darwin' in their names to the current
# version. The gcc and darwin versions are currently hardcoded.
#
# CAVEAT:
# Make a backup of /usr/local/bin and /usr/local/Cellar before
# using this script
use strict;
use warnings;
# Set parameters here. I might add command line args at some point.
#..Dry run only prints what would be done. Does not actually do it.
my $dryrun = 1;
my $new_version = 10;
my $ending = "-$new_version";
my $re_ending = qr/$ending/;
# ..In case upgrading one sub-version to another (e.g. 5.2.0 to 5.3.1)
# (moot if upgrading to new version (e.g. 5.N.M to 6.K.L)
my $old_sub = qr/5\.2\.0/;
my $new_sub = qr/$new_version\.2\.0/;
# ..To find the Darwin version, at the command line prompt enter
# uname -r
my $new_darwin_version = "17.7.0";
# No changes needed below this line (I hope)
my @gcc_N_list = glob qq("*${ending}");
print "found $#gcc_N_list files ending in '$ending'\n";
# ..If the file exists but is not a link, leave it alone.
if (-e $plain && (! -l $plain )){
print "$plain is not a link\n";
next;
}
# ..File pointed to by '$file'
my $orig = readlink($file);
if ($dryrun) {print "$file -> $orig\n";}
# __Change versions to current ones if sub-version upgrade
# ..Gnu compiler collection version
$orig =~ s/${old_sub}/${new_sub}/g;
# ..Apple Darwin version
$orig =~ s/(darwin)\d{2}\.\d\.\d/$1$new_darwin_version/;
# ..Skip non-existent files
if (! -e $orig){
print "\t$orig does not exist. Skip!\n";
next;
}
# ..Remove existing files before linking
if (-e $plain || -l $plain ){
print "$plain exists\n";
if ($dryrun) {
print "\tWould remove $plain\n";
print "\tunlink $plain\n";
}
else {
unlink $plain or die "Unable to unlink $plain $!\n";
}
}
else {
print "\t$plain does not exist would create\n";
}
# ..Finally! link the new version
if ($dryrun) {
print "\twould symlink $orig, $plain;\n";
}
else {
symlink $orig, $plain
or die "Unable to symlink $orig to $plain:$!\n";
}
}
Homebrew does not install gcc as gcc, but as gcc-5, to avoid conflicts, so be advised that going and changing things around differently is a potential recipe for mucking things up.
Some possible solutions:
Use the command brew link gcc
↳ OSX - replace gcc version with version installed via Homebrew
Create symbolic links
Read the documentation for tips on editing/modifying defaults
The first and last option is likely the more sensible route, but maybe that's not what you're looking for... The documentation will help you understand why they've done it the way they have.
