diff --git a/build/bin/write-dockerfile-debian.sh b/build/bin/write-dockerfile-debian.sh
new file mode 100755
index 00000000000..20685efd67f
--- /dev/null
+++ b/build/bin/write-dockerfile-debian.sh
@@ -0,0 +1,44 @@
+#! /usr/bin/env bash
+## Write a Dockerfile to stdout that tests that the packages listed in the debian.txt files of standard spkg exist
+## and satisfy the requirements tested by spkg-configure.m4
+set -e
+STRIP_COMMENTS="sed s/#.*//;"
+SAGE_ROOT=.
+SYSTEM_PACKAGES=$(echo $(${STRIP_COMMENTS} $SAGE_ROOT/build/pkgs/debian.txt))
+# needed for bootstrap:
+SYSTEM_PACKAGES+=" gettext autoconf automake libtool"
+CONFIGURE_ARGS="--enable-option-checking "
+for PKG_SCRIPTS in build/pkgs/*; do
+    if [ -d $PKG_SCRIPTS ]; then
+        PKG_BASE=$(basename $PKG_SCRIPTS)
+        SYSTEM_PACKAGES_FILE=$PKG_SCRIPTS/debian.txt
+        PKG_TYPE=$(cat $PKG_SCRIPTS/type)
+        if [ -f $SYSTEM_PACKAGES_FILE -a "$PKG_TYPE" = "standard" ]; then
+            SYSTEM_PACKAGES+=" "$(echo $(${STRIP_COMMENTS} $SYSTEM_PACKAGES_FILE))
+            if [ -f $PKG_SCRIPTS/spkg-configure.m4 ]; then
+                CONFIGURE_ARGS+="--with-system-$PKG_BASE=force "
+            fi
+        fi
+    fi
+done
+cat <<EOF
+ARG BASE_IMAGE=ubuntu:latest
+FROM \${BASE_IMAGE}
+RUN apt-get update &&  DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends --yes $SYSTEM_PACKAGES
+# Bootstrapping
+RUN mkdir -p /sage
+WORKDIR /sage
+ADD Makefile VERSION.txt README.md bootstrap configure.ac sage ./
+ADD m4 ./m4
+ADD build ./build
+ADD src/bin/sage-version.sh src/bin/sage-version.sh
+RUN ./bootstrap
+# Configuring
+ADD src/ext src/ext
+ADD src/bin src/bin
+ADD src/Makefile.in src/Makefile.in
+ARG EXTRA_CONFIGURE_ARGS
+RUN ./configure --enable-build-as-root $CONFIGURE_ARGS \${EXTRA_CONFIGURE_ARGS} || (echo "********** configuring without forcing ***********"; cat config.log; ./configure --enable-build-as-root; cat config.log; exit 1)
+RUN make toolchain V=0
+RUN make -j4 scipy
+EOF
diff --git a/build/pkgs/debian.txt b/build/pkgs/debian.txt
index cd9981eb57e..9d50b5b189a 100644
--- a/build/pkgs/debian.txt
+++ b/build/pkgs/debian.txt
@@ -15,5 +15,6 @@ binutils
 make
 m4
 perl
+python3-minimal    # system python for bootstrapping the build
 tar
 bc
diff --git a/build/pkgs/pari/debian.txt b/build/pkgs/pari/debian.txt
index 2005bf56647..39cd5d363b4 100644
--- a/build/pkgs/pari/debian.txt
+++ b/build/pkgs/pari/debian.txt
@@ -1 +1,3 @@
 pari-gp2c libpari-dev
+# We add these data packages because they are checked by spkg-configure.m4
+pari-elldata pari-galdata pari-galpol pari-seadata
diff --git a/build/pkgs/pari/spkg-configure.m4 b/build/pkgs/pari/spkg-configure.m4
index 8127e1c81f7..f638e4bcd2d 100644
--- a/build/pkgs/pari/spkg-configure.m4
+++ b/build/pkgs/pari/spkg-configure.m4
@@ -30,7 +30,7 @@ SAGE_SPKG_CONFIGURE([pari], [
         if test x$gp_gal_check = x16; then
             AC_MSG_RESULT([yes])
         else
-            AC_MSG_RESULT([no; cannot use system pari/GP without gapdata package])
+            AC_MSG_RESULT([no; cannot use system pari/GP without galdata package])
             AC_MSG_NOTICE([Install galdata package and reconfigure.])
             AC_MSG_NOTICE([Otherwise Sage will build its own pari/GP.])
             sage_spkg_install_pari=yes
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 00000000000..8cbe08d98b4
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,34 @@
+# Run all in parallel:
+#   tox -p auto
+# with local squid:
+#   EXTRA_DOCKER_BUILD_ARGS="--build-arg http_proxy=http://host.docker.internal:3128" tox -p auto
+[tox]
+#
+# https://hub.docker.com/_/ubuntu?tab=description
+# as of 2020-01, latest=bionic=18.04, eoan=rolling=19.10, focal=devel=20.04
+envlist = docker-ubuntu_{trusty,xenial,bionic,latest,eoan,rolling,focal,devel}
+skipsdist = true
+
+[testenv]
+envdir =
+    {toxworkdir}/docker
+# Can't use any system m4ri/m4rie apparently
+passenv =
+    EXTRA_DOCKER_BUILD_ARGS
+setenv =
+    EXTRA_CONFIGURE_ARGS=--with-system-m4ri=no --with-system-m4rie=no --with-system-givaro=no
+    ubuntu_trusty:  BASE_IMAGE=ubuntu:trusty
+    ubuntu_xenial:  BASE_IMAGE=ubuntu:xenial
+    ubuntu_bionic:  BASE_IMAGE=ubuntu:bionic
+    ubuntu_latest:  BASE_IMAGE=ubuntu:latest
+    ubuntu_eoan:    BASE_IMAGE=ubuntu:eoan
+    ubuntu_rolling: BASE_IMAGE=ubuntu:rolling
+    ubuntu_focal:   BASE_IMAGE=ubuntu:focal
+    ubuntu_devel:   BASE_IMAGE=ubuntu:devel
+
+whitelist_externals =
+    bash
+    docker
+commands =
+    bash -c 'build/bin/write-dockerfile-debian.sh > Dockerfile-debian'
+    docker build . -f Dockerfile-debian --build-arg BASE_IMAGE={env:BASE_IMAGE} --build-arg EXTRA_CONFIGURE_ARGS="{env:EXTRA_CONFIGURE_ARGS}" {env:EXTRA_DOCKER_BUILD_ARGS:}