random errors compiling 1.22.1 on armv7

[infinity0]

With latest 1.22.1 I'm getting various non-deterministic build errors on armv7 (Debian armhf). Sometimes this is:

• busy loop (of different crates), I have to manually kill it after a few days
• "failed to parse process output:" (of different crates)
• (more rare:) SIGSEGV
• (more rare:) some other memory-related message, can't remember what it was now

These are done using Debian's rustc 1.21.0 and llvm, it never gets past stage1. I also tried building from rustc's clean source code but it fails when compiling llvm, before it gets to rust.

The machine was restarted in the meantime so I lost my terminal logs, but I'll try to run these again in the next few days and recover the exact error messages. It's a very slow machine. :(

The build works if I run it on a different machine, an armv8 with a 32-bit armv7 chroot.

[infinity0]

Seems the errors are caused by OOM building on a machine with 1GB RAM.

Building on a machine with 4GB RAM gives me #45854 and setting debuginfo-only-std back to true makes the build succeed.

On a machine with 8GB RAM debuginfo-only-std = false also works.