Reason being that by default quark sets the RLIMIT_NPROC to 512 processes. When running as a non-exclusive user this limit is easily reached before even starting quark.
`resource-depletion-fix` contains a small forkbomb (`minibomb.c`) to simulate a user with > 512 processes. Compile it with `make minibomb`. When running the minibomb and quark with the same user quark fails.
The `resource-depletion-fix` branch contains a fix by setting the RLIMIT_NPROC only if the current system limit is lower than what would be set by quark. You can [download the patch](https://dirlist.friedl.net/suckless/quark/), or compile from the `resource-depletion-fix` branch.
Note that quark also has a `-n` parameter with which the max number of processes can be set as an alternative to this patch.