Removing corrupted items from a mirror

[Leo Famulari]

While trying to build the trash-cli patch on top of the master branch
(commit 2a69d4df7d7), I got the following hash mismatch while
downloading a coreutils substitute from my local mirror. When I used
mirror.hydra.gnu.org instead, the correct data was downloaded.

My question is: How can I remove this corrupted file from the mirror? I
don't know how to figure the name of the file to remove.

$ ./pre-inst-env guix build trash-cli
substitute: warning: failed to install locale: Invalid argument
@ substituter-started 
/gnu/store/vsrcn35rjpgrrak1w31m7yhc12zz3hd1-coreutils-8.24 
/gnu/store/hb25mzl9a2qjywzx41bfqgi9znc29h32-guix-0.10.0-0.e901/libexec/guix/substitute
warning: failed to install locale: Invalid argument

Found valid signature for 
/gnu/store/vsrcn35rjpgrrak1w31m7yhc12zz3hd1-coreutils-8.24
>From https://my-mirror/nar/vsrcn35rjpgrrak1w31m7yhc12zz3hd1-coreutils-8.24
Downloading vsrcn3...-coreutils-8.24 (13.8MiB installed)...
 coreutils-8.24                                                                 
                                                                                
       3.8MiB/s 00:01 | 3.5MiB transferred
@ substituter-failed /gnu/store/vsrcn35rjpgrrak1w31m7yhc12zz3hd1-coreutils-8.24 
0 hash mismatch in downloaded path 
`/gnu/store/vsrcn35rjpgrrak1w31m7yhc12zz3hd1-coreutils-8.24': expected 
a91641b020926f42d7dcbe6e9d82be3b5d39f401b7328ea6d0cd79f7893aabb0, got 
fc8cf24465d8a97fef7cc41dfccddca158b6258ad0e0929e002552d258dec7da
@ substituter-started /gnu/store/dgwa731j19lj41cds023sspcg9lqgh4j-module-import 
/gnu/store/hb25mzl9a2qjywzx41bfqgi9znc29h32-guix-0.10.0-0.e901/libexec/guix/substitute
killing process 28390
guix build: error: build failed: some substitutes for the outputs of derivation 
`/gnu/store/yk4nv2zz40f9k7hr6c9v04rn3pb5l00s-coreutils-8.24.drv' failed 
(usually happens due to networking issues); try `--fallback' to build 
derivation from source