Build tool wants lscpu, lscpu doesn't work

I’m trying to build a web server that uses the jsbundler tool parcel. Parcel, in turn, wants to call lscpu. I got lscpu by adding utillinux to my package dependencies, but when parcel calls it, I get:

⠋ Building...lscpu: failed to determine number of CPUs: /sys/devices/system/cpu/possible: No such file or directory
🚨  No entries found.
    at Bundler.bundle (/build/source/node_modules/parcel/src/Bundler.js:275:17)

builder for '/nix/store/aiqhfvi49qbr4wshmdxfnwipivdfdzp6-pdfq-ui.drv' failed with exit code 1
error: build of '/nix/store/aiqhfvi49qbr4wshmdxfnwipivdfdzp6-pdfq-ui.drv' failed

Hmm, ok. How can I get lscpu to actually work in addition to being present?

My project is here:

I’m running, which tries to build ui.nix.

Actually, it looks like lscpu is ignored if it fails. The location of the index.html argument to parcel was wrong, so parcel was giving me that ‘no entries found’ error. Fixed that and on to the next problem!

Still kind of curious about how or if one could get lscpu to work during a nix build.