source common.sh # Instantiate. drvPath=$($nixinstantiate substitutes2.nix) echo "derivation is $drvPath" # Find the output path. outPath=$($nixstore -qvvvvv "$drvPath") echo "output path is $outPath" regSub() { (echo $1 && echo "" && echo $2 && echo 3 && echo $outPath && echo Hallo && echo Wereld && echo 0) | $nixstore --register-substitutes } # Register a substitute for the output path. regSub $outPath $(pwd)/substituter.sh # Register another substitute for the output path. This one takes # precedence over the previous one. It will fail. regSub $outPath $(pwd)/substituter2.sh $nixstore -rvv "$drvPath" text=$(cat "$outPath"/hello) if test "$text" != "Hallo Wereld"; then exit 1; fi