When a fontforge script is used, if the font loaded is modified in any way, then the font modification time is set to the current time. . Initial patch in https://bugs.debian.org/774274 but withdrawn after SOURCE_DATE_EPOCH proposal. . WIP patch at https://gist.githubusercontent.com/lamby/60a545b37b778e148702c342bbf86bd9/raw/19a39af51d669fde042b261236f65ba72f75662a/903_reproducubile_build.diff . Related upstream bug at https://github.com/fontforge/fontforge/issues/2490
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