Built successfully but failed to run

[y-young]

stack build completed successfully but harmtrace recognise failed to run
output:

~/harmtrace$ stack exec harmtrace recognise -- -g pop -m mptree -v ./vamp/ -o ./ -f ./feature/ -w ./log/ -i ./test.mp3                                                  Warning (added by new or init): Specified resolver could not satisfy all dependencies. Some external packages have been added as dependencies.
You can suppress this message by removing it from stack.yaml
harmtrace: sox: rawSystem: runInteractiveProcess: exec: does not exist (No such file or directory)

All related directories permission are set to 755 and path seems all right.
OS: Ubuntu 18.04
haskell stack is the latest stable version

[jwaldmann]

.. sox: ... exec: does not exist

it seems that you need to install sox. http://sox.sourceforge.net/