Nix-shell now errors with strange message?

Am running unstable. Recently, if I opt to use nix-shell to test a package from, the shell breaks without loading. For example,

$ nix-shell -p firefox-unwrapped
these 2 paths will be fetched (62.86 MiB download, 250.65 MiB unpacked):
copying path '/nix/store/qsm1k9fxcsdwf8m98jag7ma6dg2r2z3k-nss-3.98' from ''...
copying path '/nix/store/0qswil8lgwzzshmbrma9n5fz3b6j0xdy-firefox-unwrapped-123.0.1' from ''...
build input /nix/store/xwsq5dj63439l1pphrb76zjrididi3vn-patchelf-0.15.0 /nix/store/hcrhrs1mmm2q5a3rzd6xwypqgkpm13vx-update-autotools-gnu-config-scripts-hook /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ /nix/store/ln6zld1ia7rxddmxgbpfhrmb42rbxdw8-gcc-wrapper-13.2.0 does not exist
bash: rm: No such file or directory

I don’t quite understand the last message: is it complaining it can’t fine rm, or the files listed (all do indeed exist). Anyway, if anyone has some suggestions, I would appreciate it.

OK, this problem was my fault (of course!). Within my home-manager configuration, I had statements setting up various stuff for bash, among which:

               bash = {
                  enable = true;
                  bashrcExtra = ''
                  shellAliases = {
                }; # end bash declarations

Setting a value for IFS here apparently interferes with proper parsing during nix-shell invocations; removing this statement solved the problem.