Clarification on Package Names and Versions

milahu · October 30, 2021, 9:32pm

NixOS/nix/blob/888771b4b2f153bfbf203e07d768d577ab2343e8/src/libstore/path.cc#L5-L17


      
          static void checkName(std::string_view path, std::string_view name)
          {
              if (name.empty())
                  throw BadStorePath("store path '%s' has an empty name", path);
              if (name.size() > 211)
                  throw BadStorePath("store path '%s' has a name longer than 211 characters", path);
              for (auto c : name)
                  if (!((c >= '0' && c <= '9')
                          || (c >= 'a' && c <= 'z')
                          || (c >= 'A' && c <= 'Z')
                          || c == '+' || c == '-' || c == '.' || c == '_' || c == '?' || c == '='))
                      throw BadStorePath("store path '%s' contains illegal character '%s'", path, c);
          }

how did i find this?

# generate error message
nix-build -E 'with import <nixpkgs> { }; callPackage (stdenv.mkDerivation { name = ", invalid"; }) { }' 
error: store path 'xxxx-, invalid' contains illegal character ','

# get nix source
git clone https://github.com/NixOS/nix --depth 1

# find error message
grep -rHn 'contains illegal character' nix/
nix/src/libstore/path.cc:16:            throw BadStorePath("store path '%s' contains illegal character '%s'", path, c);