Hi Ryan - thanks for the report. In Automake, those version.texi variables are updated by the auxiliary script mdate-sh. In Automake 1.16, it seems mdate-sh was changed to compute the dates using UTC (ChangeLog entry below, describing exactly what you saw, it seems), with these lines:
# Use UTC to get reproducible result. TZ=UTC0 export TZ You can get the latest mdate-sh from automake or gnulib and just put it in place independent of any other updates. If you already have the latest mdate-sh, then I'd appreciate seeing a recipe to reproduce, hopefully with smaller than gdbm itself .. --thanks, karl. 2017-09-15 Reiner Herrmann <rei...@reiner-h.de> (tiny change) mdate-sh: Ensure reproducible time output This change fixes automake bug#20314. [ https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20314 ] 'mdate-sh' pretty-prints the modification time of a file. But it's output can vary depending on the timezone of the caller. Someone in timezone GMT-12 will get a different result (day) than someone in timezone GMT+12. As this output is also used to create/update stamp files, which influence the further build process, the build result can vary. * lib/mdate-sh: Set 'TZ' to UTC which ensures reproducible output. * NEWS: Announce bug fix.