do not remove tarball until build has finished, as the build process is
fragile and dependencies that are needed are listed nowhere, meaning i
have to download several times as appeared some tool or header was
missing
ignoring and hiding errors is bad and evil, instead stop on errors so
user can see error and try to fix it
additionally fill out requirements in comment. really should test for
program existence or headers to be very nice with it
TomasM
Elan Ruusamäe