Two weeks ago, I encountered a hilarious bug with the multiple sequence alignment program MAFFT.
Who would have thought that MAFFT calls #awk to parse one of its command line arguments. Now on some systems (including Ubuntu desktop versions before this year) awk is not gawk, but an alias for mawk instead (https://superuser.com/questions/75875/awk-mawk-nawk-gawk-what) and with that one MAFFT would simply ignore the passed value for --ep.
This is now fixed in the #Bioconda package of MAFFT by requiring gawk explicitly.
awk, mawk, nawk, gawk... WHAT?
I've just started learning awk and I'm a little confused about all those versions around. Is there any "version" which is found on all Unix-like systems? Like, you know, plain vi? Does the standard...Super User