# get source code
git clone https://github.com/Perl/perl5.git perl-20140201
cd !$

# switch to branch with subroutine signatures
git checkout zefram/purple_signatures

# build Perl
sh Configure -de -Dusedevel -Dprefix=$HOME/perl5/perlbrew/perls/perl-zefram-purple_signatures
make
make test
make install

# fix up the names of the executables
cd ~/perl5/perlbrew/perls/perl-zefram-purple_signatures/bin
rename 's/5.19.9$//' *

# oh, but perldoc has 5.19.9 in the shebang line...
ln -s perl perl5.19.9

# now try it out!
perlbrew switch perl-zefram-purple_signatures