My nightly script that builds rustc to check that its builds are reproducible recently discovered that the cargo binary differed. A git bisect pointed to f6855eacd1544cea34134dfdb7c7f426e5b0442a, which updates cargo. Bisecting that revision range led to 0e26eae.

I can verify this by checking out cargo, making an exact copy of it in a different directory, and then building them in release mode with a .cargo/config that adds --remap-path-prefix appropriately.

I tested with both rustc 1.43.0 and the nightly builds over the past few days. With the Cargo commit above I see differences in the output files and with its parent I do not.