lukas@wolfgang ~/s/depot (canon) [1]> nix repl .
Welcome to Nix version 2.3.10. Type :? for help.
Loading '.'...
Added 19 variables.
nix-repl> nix.readTree
{ __functor = «lambda @ /home/lukas/src/depot/nix/readTree/default.nix:80:16»; __readTree = [ ... ]; tests = «derivation /nix/store/n302bv981765cnd2dd30w47fn7rkgy4i-testsuite-readTree-successful.drv»; }
nix-repl> nix.readTree.tests
«derivation /nix/store/n302bv981765cnd2dd30w47fn7rkgy4i-testsuite-readTree-successful.drv»
nix-repl> :b nix.readTree.tests
[1 built]
this derivation produced the following outputs:
out -> /nix/store/ybcgvx7icybg71y7qrx539ngs2h5fcwl-testsuite-readTree-successful
lukas@wolfgang ~/s/depot (canon)> nix-build -A nix.readTree.tests
error: the expression selected by the selection path 'nix.readTree.tests' should be a set but is a function
lukas@wolfgang ~/s/depot (canon) [1]>