"compile mongodb" function in sys-perf doesn't install Python dependencies

[2019/02/14 05:05:01.706] # This script converts the generated version string into a sanitized version string for

[2019/02/14 05:05:01.706] # use by scons and uploading artifacts as well as information about for the scons cache.

[2019/02/14 05:05:01.706] MONGO_VERSION=$MONGO_VERSION USE_SCONS_CACHE=true /opt/mongodbtoolchain/v3/bin/python2 buildscripts/generate_compile_expansions.py --out compile_expansions.yml

[2019/02/14 05:05:06.295] Traceback (most recent call last):

[2019/02/14 05:05:06.295]   File "buildscripts/generate_compile_expansions.py", line 16, in <module>

[2019/02/14 05:05:06.298]     import yaml

ImportError: No module named yaml

[2019/02/14 05:05:06.298] Command failed: command [pid=2443] encountered problem: exit status 1