Projects with MSAN disabled because of upgrade to Ubuntu 20.04

[jonathanmetzman]

You are probably reading this issue because MSAN was disabled in your project during the upgrade to Ubuntu 20.04
Note that if your project was broken before the upgrade it is not included on this list.

Ubuntu 16.04 had prebuilt MSAN libraries, but Ubuntu 20.04 does not and we don’t expect this to change.
This allowed many projects to use MSAN easily, because when using MSAN all executed code must be instrumented with MSAN.
This means that to re-enable MSAN, your project can no longer link against the versions of these libraries provided by apt.
Instead your project must build these libraries from source and instrument them with MSAN using MSAN builds.
If you are able and willing to make this change, please submit the change as a pull request and comment here that you have fixed the issue, so we can track fixes.
Thank you!

[maflcko]

It looks like the MSAN upgrade may fix some (presumed) false positives. One example: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34844 was only reproducible on OSS-Fuzz Xenial, but not OSS-Fuzz Focal or locally with MSAN/valgrind.

[jonathanmetzman]

Yes I'm aware. I'm going to be fixing these later next week.

[dlemstra]

Would it possible to add some information on how we can test if we could re-enable MSAN again @jonathanmetzman? The other issue mentions that some tests where done and I am wondering if it is possible to share some extra information?

[maflcko]

I guess the best way forward now would be to just re-enable it and see if any issues arise, then either fix them or disable it again?

[jonathanmetzman]

Yup!