diff --git a/gdal/ci/travis/trusty_clang/before_install.sh b/gdal/ci/travis/trusty_clang/before_install.sh
index 3d19a7e07653..2461ad4e1390 100755
--- a/gdal/ci/travis/trusty_clang/before_install.sh
+++ b/gdal/ci/travis/trusty_clang/before_install.sh
@@ -11,23 +11,31 @@ sudo add-apt-repository -y ppa:ubuntugis/ubuntugis-unstable
 #sudo add-apt-repository -y ppa:marlam/gta
 sudo apt-get update
 
+# install test dependencies
+# note: pip 9 is installed on the box, but it hits a strange error after upgrading setuptools.
+# so we install a newer pip first.
+sudo apt-get remove -y python-*
+sudo apt-get install python-minimal
+curl -sSL 'https://bootstrap.pypa.io/get-pip.py' | sudo python
+(cd autotest; sudo -H pip install -U -r ./requirements.txt)
+
+sudo pip install lxml flake8 numpy
+
 # MSSQL: server side
 docker pull microsoft/mssql-server-linux:2017-latest
 sudo docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=DummyPassw0rd'  -p 1433:1433 --name sql1 -d microsoft/mssql-server-linux:2017-latest
 sleep 10
 docker exec -it sql1 /opt/mssql-tools/bin/sqlcmd -l 30 -S localhost -U SA -P DummyPassw0rd -Q "CREATE DATABASE TestDB;"
 
-sudo apt-get install -y --allow-unauthenticated ccache python-numpy libpng12-dev libjpeg-dev libgif-dev liblzma-dev libgeos-dev libcurl4-gnutls-dev libproj-dev libxml2-dev libexpat-dev libxerces-c-dev libnetcdf-dev netcdf-bin libpoppler-dev libspatialite-dev gpsbabel swig libhdf4-alt-dev libhdf5-serial-dev libpodofo-dev poppler-utils libfreexl-dev unixodbc-dev libwebp-dev  libepsilon-dev  liblcms2-2 libpcre3-dev mercurial cmake libcrypto++-dev postgresql-9.3-postgis-2.2 postgresql-9.3-postgis-scripts libpq-dev
+sudo apt-get install -y --allow-unauthenticated ccache libpng12-dev libjpeg-dev libgif-dev liblzma-dev libgeos-dev libcurl4-gnutls-dev libproj-dev libxml2-dev libexpat-dev libxerces-c-dev libnetcdf-dev netcdf-bin libpoppler-dev libspatialite-dev gpsbabel swig libhdf4-alt-dev libhdf5-serial-dev libpodofo-dev poppler-utils libfreexl-dev unixodbc-dev libwebp-dev  libepsilon-dev  liblcms2-2 libpcre3-dev mercurial cmake libcrypto++-dev postgresql-9.3-postgis-2.2 postgresql-9.3-postgis-scripts libpq-dev
 # libgta-dev
-sudo apt-get install -y python-lxml
-sudo apt-get install -y python-pip
 sudo apt-get install -y libqhull-dev
 sudo apt-get install -y libogdi3.2-dev
 # MONO
 sudo apt-get install -y mono-mcs libmono-system-drawing4.0-cil
 # Boost for Mongo
 #sudo apt-get install -y libboost-regex-dev libboost-system-dev libboost-thread-dev
-sudo pip install flake8
+
 sudo apt-get install doxygen texlive-latex-base
 # flake8 codes to just emulate pyflakes (http://flake8.pycqa.org/en/latest/user/error-codes.html)
 FLAKE8="flake8 --select=F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F721,F722,F811,F812,F821,F822,F823,F831,F841,F901"
diff --git a/gdal/ci/travis/trusty_clang/install.sh b/gdal/ci/travis/trusty_clang/install.sh
index 4675e008c994..662c0c746b81 100755
--- a/gdal/ci/travis/trusty_clang/install.sh
+++ b/gdal/ci/travis/trusty_clang/install.sh
@@ -41,7 +41,7 @@ make USER_DEFS="-Wextra -Werror" -j3
   export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
   export PATH=$JAVA_HOME/jre/bin:$PATH
   java -version
-  make
+  (make 2>/tmp/log.txt || cat /tmp/log.txt)
   mv java.opt.bak java.opt
 )
 
@@ -51,7 +51,7 @@ make
 cd ../..
 cd swig/csharp
 make generate
-make
+make 2>/tmp/log.txt || cat /tmp/log.txt
 cd ../..
 sudo rm -f /usr/lib/libgdal.so*
 sudo rm -f /usr/include/gdal*.h /usr/include/ogr*.h /usr/include/gnm*.h /usr/include/cpl*.h 
diff --git a/gdal/ci/travis/trusty_clang/script.sh b/gdal/ci/travis/trusty_clang/script.sh
index 2c88405419b7..53e85d2f3ab6 100755
--- a/gdal/ci/travis/trusty_clang/script.sh
+++ b/gdal/ci/travis/trusty_clang/script.sh
@@ -36,9 +36,6 @@ wget http://download.osgeo.org/gdal/data/pgeo/PGeoTest.zip
 unzip PGeoTest.zip
 cd ../../..
 
-# install test dependencies
-sudo -H pip install -U -r ./requirements.txt
-
 export PYTHONPATH=/usr/lib/python2.7/dist-packages
 
 # Run ogr_fgdb.py in isolation from the rest