`dwarffs` fails to build against latest `nix-2.19.2` release

[trofi]

The build fails as:

g++ -c -g -std=c++17 -Wall -Os dwarffs.cc -o dwarffs.o
dwarffs.cc:10:10: fatal error: fs-accessor.hh: No such file or directory
   10 | #include "fs-accessor.hh"
      |          ^~~~~~~~~~~~~~~~
compilation terminated.

Possibly caused by NixOS/nix@1a902f5

[trofi]

#30 fixed the build against the latest nix for me.