agent:2020/01/13 12:51:01 build.go:220: FAILED: gen/services/metrics/public/cpp/ukm_builders.cc gen/services/metrics/public/cpp/ukm_builders.h gen/services/metrics/public/cpp/ukm_decode.cc gen/services/metrics/public/cpp/ukm_decode.h 
agent:2020/01/13 12:51:01 build.go:220: /usr/bin/python2 ../../3rdparty/chromium/tools/metrics/ukm/gen_builders.py --input ../../3rdparty/chromium/tools/metrics/ukm/ukm.xml --output gen/services/metrics/public/cpp
agent:2020/01/13 12:51:01 build.go:220: Traceback (most recent call last):
agent:2020/01/13 12:51:01 build.go:220:   File "../../3rdparty/chromium/tools/metrics/ukm/gen_builders.py", line 16, in <module>
agent:2020/01/13 12:51:01 build.go:220:     import ukm_model
agent:2020/01/13 12:51:01 build.go:220:   File "/home/qt/work/qt/qtwebengine/src/3rdparty/chromium/tools/metrics/ukm/ukm_model.py", line 10, in <module>
agent:2020/01/13 12:51:01 build.go:220:     import models
agent:2020/01/13 12:51:01 build.go:220:   File "/home/qt/work/qt/qtwebengine/src/3rdparty/chromium/tools/metrics/ukm/../common/models.py", line 17, in <module>
agent:2020/01/13 12:51:01 build.go:220:     from xml.dom import minidom
agent:2020/01/13 12:51:01 build.go:220: ImportError: No module named xml.dom