it's trying to use the read-only filesystem and failing as a result of it (should probably use the `~/.guix-profile/bin/p2pool`):

Steps to reproduce:
1. Invoke `guix shell monero-gui@0.17.3.2 -- monero-wallet-gui`
2. Create a new wallet (user-friendly GUI)
3. Set the wallet to use a local node and wait for it to compute the blockchain until fully synced (Settings->Node->Local node and Start the daemon)
* Optionally consider adding `--prune-blockchain` for daemon startup flags for significantly reduced blockchain (~40 GB) to avoid computing the ~120 GB node or using Bootstrap Address to download the blockchain already computed
4. Try to launch the miner using p2pool pool and expect failure above (Advanced->Mining->Mining mode=P2Pool and Start mining)

-- 
-- Jacob Hrbek #StandWithUkraine