As other already mentioned you can mount a RAM disk yourself to where the target folder would be placed. Alternatively you can change where cargo places its artifacts to somewhere you already have a ram disk mounted, e.g. /tmp

https://doc.rust-lang.org/cargo/reference/config.html#buildtarget-dir

I had a similar construct in my bashrc and forgot the quotes. It didn’t throw an error but also didn’t work. Took quite a while to find the issue. So personally, I would recommend trying to quote correctly whenever possible.