= mystery byte increments in jar format =

I've been working on reproducible jars, and I have fixed the timestamps by running the builds using `faketime`.  Now the contents of the jars are exactly the same when I unzip them, including the timestamps, but the jars themselves do not have the same hash.  Using `vbindiff`, I can see a smattering of bytes that are different, with almost always the same pattern: one build's byte will be +1 from the others, i.e. one has 98 and the other has 99, or 56 and 57.  It seems that this byte is some kind of separator between class names.

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Hi!  Please share output of e.g. "diff -u $<(xxd a.jar) $<(xxd b.jar)" (assuming a Bash shell).  They're only .ZIP files;  it sounds like you're seeing differences in the file header records at the end of the archive, so we can try to interpret what they mean.  https://en.wikipedia.org/wiki/ZIP_%28file_format%29#File_headers

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`diff` does a poor job of showing differences, so here's a screenshot from `meld`:

[[attachment:cachewordlib-bin-diff.png]]

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The differences shown here are file mtimes in the ZIP file.  A difference of 0x01 means 2 seconds' difference.  So I'm afraid faketime isn't working as expected for you.

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Serves me right for using `unzip -lv` versus `zipinfo -lv`.  This 2 second difference is clear to see when comparing `zipinfo -lv`.