diff --git a/.github/workflows/build_ubuntu-20.04_without_x.sh b/.github/workflows/build_ubuntu-20.04_without_x.sh
new file mode 100755
index 00000000000..5df3a0b7e33
--- /dev/null
+++ b/.github/workflows/build_ubuntu-20.04_without_x.sh
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+
+# The make step requires something like:
+# export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$PREFIX/lib"
+# further steps additionally require:
+# export PATH="$PATH:$PREFIX/bin"
+
+# fail on non-zero return code from a subprocess
+set -e
+
+# print commands
+set -x
+
+if [ -z "$1" ]; then
+    echo "Usage: $0 PREFIX"
+    exit 1
+fi
+
+# Adding -Werror to make's CFLAGS is a workaround for configuring with
+# an old version of configure, which issues compiler warnings and
+# errors out. This may be removed with upgraded configure.in file.
+makecmd="make"
+if [[ "$#" -eq 2 ]]; then
+    makecmd="make CFLAGS='$CFLAGS $2' CXXFLAGS='$CXXFLAGS $2'"
+fi
+
+# non-existent variables as an errors
+set -u
+
+export INSTALL_PREFIX=$1
+
+./configure \
+    --prefix="$INSTALL_PREFIX/" \
+    --enable-largefile \
+    --with-cxx \
+    --with-zstd \
+    --with-bzlib \
+    --with-blas \
+    --with-lapack \
+    --with-readline \
+    --without-openmp \
+    --with-pdal \
+    --without-pthread \
+    --with-tiff \
+    --with-freetype \
+    --with-freetype-includes="/usr/include/freetype2/" \
+    --with-proj-share=/usr/share/proj \
+    --with-geos \
+    --with-sqlite \
+    --with-fftw \
+    --with-netcdf
+
+eval $makecmd
+make install
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index d2b9ea872ef..1fb98429afb 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -7,13 +7,21 @@ on:
 
 jobs:
   build-and-test:
-    name: ${{ matrix.os }} tests
+    name: ${{ matrix.name }} tests
 
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os:
-          - ubuntu-20.04
+        include:
+          - name: "20.04"
+            os: ubuntu-20.04
+            config: ubuntu-20.04
+          # This is without optional things but it still keeps things useful,
+          # so, e.g., without OpenMP, but with PDAL. Code or tests should be written
+          # so that test pass even when these optional things are not present.
+          - name: "minimum config"
+            os: ubuntu-20.04
+            config: ubuntu-20.04_without_x
       fail-fast: false
 
     steps:
@@ -39,7 +47,7 @@ jobs:
           echo "LD_LIBRARY_PATH=$HOME/install/lib" >> $GITHUB_ENV
 
       - name: Build
-        run: .github/workflows/build_${{ matrix.os }}.sh $HOME/install
+        run: .github/workflows/build_${{ matrix.config }}.sh $HOME/install
 
       - name: Add the bin directory to PATH
         run: |