Hacking perl the intepreter

gistfile1.txt

# Configure with debugging allows using PerlIO_printf(Perl_debug_log, "", …);
./Configure -des -Dusedevel -Dprefix=$HOME/localperl -DDEBUGGING

# But -DDEBUGGING does not seem to work so I use this:
./Configure -des -Dusedevel -Dprefix=$HOME/localperl -A ccflags=-DDEBUGGING

# Just build a bare bones executable
make miniperl

# Run code
./miniperl -Ilib -wlE '…'

# Execute some tests
./miniperl -Ilib lib/warnings.t

# Duh
make minitest