Building docker image fails

[fanginoort]

[...]
Step 11/16 : RUN mkdir freedom-e-sdk
 ---> Running in 1fc1c11d1ec9
Removing intermediate container 1fc1c11d1ec9
 ---> c5b5c3963ee6
Step 12/16 : COPY ./ freedom-e-sdk/
 ---> 3cb195c59994
Step 13/16 : RUN make -C ./freedom-e-sdk virtualenv
 ---> Running in 141aee29461b
make: *** No rule to make target 'virtualenv'.  Stop.
make: Entering directory '/freedom-e-sdk'
make: Leaving directory '/freedom-e-sdk'
The command '/bin/sh -c make -C ./freedom-e-sdk virtualenv' returned a non-zero code: 2