tor compilation hangs frequently when building Windows testbuilds

I have seen frequent hangs when building tor for Windows lately, the output ps gives me always indicates that's due to Rust involvement:

boklm    27911  0.0  0.0  21032  2884 ?        S    11:10   0:00 /bin/bash -c ( cd "/var/tmp/build/tor-911f95ed9203/src/rust" ; \ .CARGO_TARGET_DIR="/var/tmp/build/tor-911f95ed9203/src/rust/target" \ .cargo build --release  \ .--frozen \ .--manifest-path "/var/tmp/build/tor-911f95ed9203/src/rust/tor_rust/Cargo.toml" )
boklm    27912  0.0  0.0  21040  2144 ?        S    11:10   0:00 /bin/bash -c ( cd "/var/tmp/build/tor-911f95ed9203/src/rust" ; \ .CARGO_TARGET_DIR="/var/tmp/build/tor-911f95ed9203/src/rust/target" \ .cargo build --release  \ .--frozen \ .--manifest-path "/var/tmp/build/tor-911f95ed9203/src/rust/tor_rust/Cargo.toml" )
boklm    27913  0.0  0.1  59928 12672 ?        Sl   11:10   0:00 cargo build --release --frozen --manifest-path /var/tmp/build/tor-911f95ed9203/src/rust/tor_rust/Cargo.toml
boklm    27993  0.0  1.5 291156 124976 ?       Sl   11:10   0:00 rustc --crate-name external external/lib.rs --crate-type lib --emit=dep-info,link -C opt-level=3 -C panic=abort -C debuginfo=2 -C metadata=0f05d544ad739841 -C extra-filename=-0f05d544ad739841 --out-dir /var/tmp/build/tor-911f95ed9203/src/rust/target/x86_64-pc-windows-gnu/release/deps --target x86_64-pc-windows-gnu -L dependency=/var/tmp/build/tor-911f95ed9203/src/rust/target/x86_64-pc-windows-gnu/release/deps -L dependency=/var/tmp/build/tor-911f95ed9203/src/rust/target/release/deps --extern libc=/var/tmp/build/tor-911f95ed9203/src/rust/target/x86_64-pc-windows-gnu/release/deps/liblibc-705cca6c457715c2.rlib --extern smartlist=/var/tmp/build/tor-911f95ed9203/src/rust/target/x86_64-pc-windows-gnu/release/deps/libsmartlist-42b40589a0bfb5d0.rlib --extern tor_allocate=/var/tmp/build/tor-911f95ed9203/src/rust/target/x86_64-pc-windows-gnu/release/deps/libtor_allocate-3bee9e10e00146b6.rlib

I might have seen this once with macOS builds but I think never with Linux ones.