* Mattia Rizzolo <mattia@mapreri.org>, 2015-10-20, 16:18:
[ -n "$TMP" -a ! -d "$TMP" ] && mkdir -p "$TMP" || true [ -n "$TMPDIR" -a ! -d "$TMPDIR" ] && mkdir -p "$TMPDIR" || true
POSIX says that one should use $TMPDIR as a directory for temporary files. I you know software that uses $TMP, $TEMP, $TEMPDIR or something else for this purpose, please file bugs. :)
umh, something tells me this is not enough: hooks are run as root, while the build is not, so the build user would not be able to write there. Currently the build username or user ID is not exported to the hooks, so the better you can do is to chmod 777 TMPDIR and TMP (programs using /tmp should be able to use that securely anyway...)
ITYM 1777. Without sticky bit set, other users could remove your temporary files or directories and replace them with their own, which would not end well.
-- Jakub Wilk