diff --git a/.travis.yml b/.travis.yml
index 325cdf12..9cab0f95 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -85,9 +85,13 @@ matrix:
     #  os: osx
     - env: PAGMO_PLUGINS_NONFREE_BUILD="OSXPython37"
       os: osx
-      osx_image: xcode11.3
+      osx_image: xcode10.3
 script:
 - mkdir build
 - cd build
-- source ../tools/install_deps.sh
-- source ../tools/install_travis.sh
+# NOTE: currently, travis does not stop automatically if one of these
+# 2 scripts returns an error code. Thus, we run them together as a single
+# command, so that if install_deps.sh fails the whole build fails immediately
+# rather than executing install_travis.sh as well. See
+# https://github.com/travis-ci/travis-ci/issues/1066
+- ../tools/install_deps.sh && ../tools/install_travis.sh
diff --git a/tools/install_deps.sh b/tools/install_deps.sh
index 984cac65..04d3aed1 100644
--- a/tools/install_deps.sh
+++ b/tools/install_deps.sh
@@ -9,9 +9,9 @@ set -e
 # For the non manylinux builds (i.e. pip) we use conda and thus install and activate a conda environment
 if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" != manylinux* ]]; then
     if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then
-        wget https://repo.continuum.io/miniconda/Miniconda2-latest-MacOSX-x86_64.sh -O miniconda.sh;
+        wget https://repo.continuum.io/miniconda/Miniconda3-latest-MacOSX-x86_64.sh -O miniconda.sh;
     else
-        wget https://repo.continuum.io/miniconda/Miniconda2-latest-Linux-x86_64.sh -O miniconda.sh;
+        wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh;
     fi
     export deps_dir=$HOME/local
     export PATH="$HOME/miniconda/bin:$PATH"
@@ -19,16 +19,16 @@ if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" != manylinux* ]]; then
     conda config --add channels conda-forge --force
 
     # All builds will need these
-    conda_pkgs="boost cmake pagmo-devel"
+    conda_pkgs="boost cmake pagmo-devel cxx-compiler"
 
     # Only Python builds will need these
     if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" == "Python37" || "${PAGMO_PLUGINS_NONFREE_BUILD}" == "OSXPython37" ]]; then
         conda_pkgs="$conda_pkgs python=3.7 pygmo pybind11" 
     fi
 
-    if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" == OSX* ]]; then
-        conda_pkgs="$conda_pkgs clangdev<10"
-    fi
+    #if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" == OSX* ]]; then
+    #    conda_pkgs="$conda_pkgs clangdev<10"
+    #fi
 
     if [[ "${PAGMO_PLUGINS_NONFREE_BUILD}" == Python* ]]; then
         conda_pkgs="$conda_pkgs graphviz doxygen sphinx breathe"