I just reproduced Coldcard Build v5.1.2.
This process checks the compiled binary against the binary published by Coinkite. If you see the "SUCCESS." message, the binaries are identical, except of 64 bytes (Coinkite's signature).
These bytes are removed using "TRIM_SIG = sed -e 's/^00003f[89abcdef]0 .*/(firmware signature here)/' " in the Makefile.
If you wonder why these checksums in (~/firmware/stm32/built) of the compiled files are different, compare to the binary you have downloaded from
https://coldcard.com/downloads/, it's exactly due to those 64 signature bytes.
Full video here:
Here is my copy-n-paste process/instruction for the latest version.

Gist
REPRO COLDCARD BUILD
REPRO COLDCARD BUILD. GitHub Gist: instantly share code, notes, and snippets.
Just in case you want to send me some sats:
lnurl1dp68gurn8ghj7ampd3kx2ar0veekzar0wd5xjtnrdakj7tnhv4kxctttdehhwm30d3h82unvwqhhxmrfva58gumrwfjk2m34xgfgqgqd 🧡
This PR

GitHub
Update index.html by xavierfiechter · Pull Request #71 · coinkite/bitcoinbinary.org
CC v5.1.2
adds the proof to BitcoinBinary.org
FIN.