bugfix: lib/common.Makefile: Compression: %.gz <-> %: only run command if target does not exist, to avoid overwriting the target when the compressed or uncompressed version is newer than it. the difference in mtimes can arise when one file is created after the other, and should not cause the opposite operation to be performed to try to make the other file up-to-date (leading to an infinite back-and-forth of creating one file from the other).
bugfix: lib/common.Makefile: Compression: %.gz <-> %: only run command if target does not exist, to avoid overwriting the target when the compressed or uncompressed version is newer than it. the difference in mtimes can arise when one file is created after the other, and should not cause the opposite operation to be performed to try to make the other file up-to-date (leading to an infinite back-and-forth of creating one file from the other).