troubleshoot wheel

Author: edenhill

.travis.yml

@@ -45,7 +45,7 @@ jobs:
 # Install cibuildwheel if this is a tagged PR
 before_install:
   - if [[ $TRAVIS_OS_NAME == "osx" ]]; then tools/prepare-osx.sh ${INTERPRETER_VERSION} /tmp/venv && source /tmp/venv/bin/activate; fi
-  - if [[ -n $TRAVIS_TAG && -n $CIBW_BEFORE_BUILD ]]; then pip install -r tools/requirements-manylinux.txt --force-reinstall; fi
+  - if [[ -n $TRAVIS_TAG && -n $CIBW_BEFORE_BUILD ]]; then pip install -U -r tools/requirements-manylinux.txt --force-reinstall ; which wheel ; wheel version ; wheel -h ; fi
 
 # Install interceptors
 # Install librdkafka if not CIBW_BEFORE_BUILD