If you specify jobs = 0 in .cargo/config, your cargo build invocations will hang forever without output. Note that if you try to invoke cargo build -j 0 it will warn you:

$ cargo build -j 0
error: jobs must be at least 1

Steps

1. Place a .cargo/config in any valid location with the following content:

    [build]
    jobs = 0
   

2. Run cargo build.

3. You will never reach step 3.

Possible Solution(s)

Check for jobs being 0 when reading the config file.

Notes

Output of cargo version: latest master commit, 0b2059e.