Editing proc-macro crate = undefined symbol

[sgrif]

Note: This is with incremental-comp turned off, and a compiler built yesterday.

Occasionally when working on Diesel's codegen crates, I'll get an error like this:

error: dlsym(0x113560e00, __rustc_derive_registrar__55df2b44c5129c66de0914ff53563457_89): symbol not found
   --> diesel/src/lib.rs:121:1
    |
121 | extern crate diesel_derives2;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The only fix when this happens is to cargo clean. It randomly happens when I change some code, but not 100% of the time.

[nox]

I can confirm this happens.

@sgrif As a workaround to not clean everything, I do:

find target -name \*culprit-crate-name\* | xargs rm -rf

[alexcrichton]

I think this was fixed by #47494, so closing.

[dtolnay]

Reopening because #47494 merged on Jan 18 and this was reported on a compiler built Jan 31.

[alexcrichton]

Oh oops, indeed!

[Enselic]

Triage: Is this still a problem? Wanted to ask since 5 years have passed and circumstances might have changed.