+ # We are creating files for mass distribution, so work harder to make smaller files.
+ $ENV{'GZIP'} = '-9';
+ $ENV{'BZIP2'} = '-9';
+ # xz documents minimum file sizes for levels higher than -6 to be useful and each
+ # requires more RAM on the decompressing system. Exim tarball currently 24MiB so
+ # using -8.
+ $ENV{'XZ_DEFAULTS'} = '-8';