brew --prefix circos
/usr/local/opt/circos
(base) Ellas-MacBook-Pro:bin elladouglas$ circos -modules
ok 1.29 Carp
ok 0.36 Clone
ok 2.63 Config::General
ok 3.40 Cwd
ok 2.145 Data::Dumper
ok 2.52 Digest::MD5
ok 2.84 File::Basename
ok 3.40 File::Spec::Functions
ok 0.23 File::Temp
ok 1.51 FindBin
ok 0.39 Font::TTF::Font
ok 2.71 GD
ok 0.2 GD::Polyline
ok 2.39 Getopt::Long
ok 1.16 IO::File
perl circos -conf circos.conf
*** REQUIRED MODULE(S) MISSING OR OUT-OF-DATE ***
You are missing one or more Perl modules, require newer versions, or some modules failed to load. Use CPAN to install it as described in this tutorial
http://www.circos.ca/documentation/tutorials/configuration/perl_and_modules
missing GD
error Can't locate GD.pm in @INC