Never seen that before. My first guess would be that rustc is somehow unable to find one of the .dlls it needs... but I've never seen anyone with that issue.
How did you install Rust? Are you using rustup, an installer, or just unpacking an archive somewhere? Did you update it the same way, or did you change to a different method? Also, is this for cargo build, or is it some other command?
Edit: Also, do you remember what the previous version that did work was?
I have a very vague recollection from years ago of a rustup install that failed part way through, leaving a corrupt installation that I had to reinstall to get it working. If it never got around to installing one of the compiler libraries, that might explain it.
Also check that you have free space on your primary drive. My 1.68.2 toolchain takes ~1.5GB, so as long as you have a few GB free you should be okay.
re-installed rust 1.72 with rustup and now encountering the following problem:
cargo clean && cargo build
Updating crates.io index
warning: spurious network error (3 tries remaining): [35] SSL connect error (schannel: next InitializeSecurityContext failed: Unknown error (0x80092012) - The revocation function was unable to check revocation for the certificate.)
warning: spurious network error (2 tries remaining): [35] SSL connect error (schannel: next InitializeSecurityContext failed: Unknown error (0x80092012) - The revocation function was unable to check revocation for the certificate.)
warning: spurious network error (1 tries remaining): [35] SSL connect error (schannel: next InitializeSecurityContext failed: Unknown error (0x80092012) - The revocation function was unable to check revocation for the certificate.)
error: failed to get assert_approx_eq as a dependency of package
I guess we are supposed to get this error if the computer is behind a corporate firewall