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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
08712 Plugins Major Always Jul 8, 2023, 20:34 Jul 9, 2023, 13:19
Tester Bletch View Status Public Platform MAME (Official Binary)
Assigned To Resolution Invalid report OS Windows 10/11 (64-bit)
Status [?] Closed Driver
Version 0.256 Fixed in Version Build
Fixed in Git Commit Github Pull Request #
Summary 08712: bit32 LUA module does not seem to be present in MAME 0.256 Windows builds
Description I've added this to my plugins/boot/lua to test for the bit32 LUA module

assert(type(bit32) == "table", "Expected bit32 to be present")

When I build the MAME tip myself, this works. When I download the MAME 0.256 Windows builds from, this line fails.

It is my understanding that bit32 is a standard LUA module that plugins are supposed to be able to rely on being present. I'm asking because there is a BletchMAME bug report that I've been able to trace to bit32 not being present:
Steps To Reproduce 1. Download MAME 0.256 release binaries for WIndows
2. Add 'assert(type(bit32) == "table", "Expected bit32 to be present")' somewhere to plugins/boot.ini
3. Run MAME - the assert fails
Additional Information
Github Commit
Regression Version
Affected Sets / Systems
Attached Files
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User avatar
Jul 9, 2023, 01:55
It’s a deprecated feature that was no longer needed when native integer support was added in Lua 5.3, and was removed from Lua 5.4. We updated to Lua 5.4 for MAME 0.253, as noted in the executive summary (which also mentions removal of the deprecated bitlib):
User avatar
Jul 9, 2023, 13:19
Makes sense. Is there a reason that a clean update from git and full build with the MAME development tools would create a build where bit32 seems to be present?