hey i am kinda new to Nixos love it so far, but i have run in to a problem with tinygo and teensy i have installed teensy-loader-cli(cant find any other packages) but tinygo expect teensy_loader_cli, whats the nix way of symlinking or solving this problem?

Indeed, they rename the binary here, not sure why, you should fill a bug report nixpkgs/pkgs/development/embedded/teensy-loader-cli/default.nix at 44733514b72e732bd49f5511bd0203dea9b9a434 · NixOS/nixpkgs · GitHub

In the meantime, you can add to your list of packages

(pkgs.runCommand "teensy-loader-cli" {} ''
  mkdir -p $out/bin
  ln -s ${lib.getBin pkgs.teensy-loader-cli}/bin/teensy-loader-cli $out/bin/teensy_loader_cli

(Not tested) to get both versions.

that worked almost perfect just needed to remove that ; at the end of the command, thank you vary much. ill file a bug report and see what they say