How to fix `failed to increase jobserver pipe capacity from 4096 to 8192; jobserver otherwise might deadlock` error from cargo/rustc - rust

Question

When performing some rust compilation tasks such as running cargo build or cargo xtask install, occasionally the compiler will crash with an error message:
Caused by:
process didn't exit successfully: `rustc - --crate-name ___ --print=file-names -C link-arg=-fuse-ld=lld --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit status: 101)
--- stderr
thread 'rustc' panicked at 'failed to create jobserver: Custom { kind: PermissionDenied, error: "failed to increase jobserver pipe capacity from 4096 to 8192; jobserver otherwise might deadlock" }', compiler/rustc_data_structures/src/jobserver.rs:23:38
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: rustc 1.56.0-nightly (0035d9dce 2021-08-16) running on x86_64-unknown-linux-gnu
note: compiler flags: -C link-arg=-fuse-ld=lld --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro
query stack during panic:
end of query stack
This is occurring on the latest Rust nightly toolchain that includes a working RLS as of the time of posting, rustc 1.56.0-nightly (0035d9dce 2021-08-16)
OS is Debian Linux

Answer 1

This bug is likely caused by a PR merged into jobserver-rs that aims to increase the jobserver pipe buffer capacity on Linux: https://github.com/alexcrichton/jobserver-rs/pull/34
This seems to have created a regression and so was reverted here: https://github.com/alexcrichton/jobserver-rs/pull/35
However, since no new rust nightlies have been minted in a couple of weeks due to rls failing to build, the bug persists in the latest nightly.
The fix is to revert to an older rust nightly and wait for a new working nightly to be released with rls support which will include the revert for the breaking commit to jobserver-rs.