Merge PR#497: [travis] [8.6.only] Backport latest changes from trunk.

22 files changed, 268 insertions, 75 deletions

diff --git a/.travis.yml b/.travis.yml
index f609852bc..7138d5c61 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,7 @@
 dist: trusty
+# Travis builds are slower using sudo: false (the container-based
+# infrastructure) as of March 2017; see
+# https://github.com/coq/coq/pull/467 for some discussion.
 sudo: required
 # Until Ocaml becomes a language, we set a known one.
 language: c
@@ -29,6 +32,7 @@ env:
   - TEST_TARGET="ci-coquelicot"
   - TEST_TARGET="ci-geocoq"
   - TEST_TARGET="ci-fiat-crypto"
+  - TEST_TARGET="ci-fiat-parsers"
   - TEST_TARGET="ci-flocq"
   - TEST_TARGET="ci-hott"
   - TEST_TARGET="ci-iris-coq"
diff --git a/Makefile.ci b/Makefile.ci
index e4b5832f6..897318c4d 100644
--- a/Makefile.ci
+++ b/Makefile.ci
@@ -1,5 +1,5 @@
 CI_TARGETS=ci-all ci-hott ci-math-comp ci-compcert ci-sf ci-cpdt \
-           ci-color ci-math-classes ci-tlc ci-fiat-crypto \
+           ci-color ci-math-classes ci-tlc ci-fiat-crypto ci-fiat-parsers \
            ci-coquelicot ci-flocq ci-iris-coq ci-metacoq ci-geocoq \
            ci-unimath
 
diff --git a/dev/ci/ci-basic-overlay.sh b/dev/ci/ci-basic-overlay.sh
new file mode 100644
index 000000000..241ec3586
--- /dev/null
+++ b/dev/ci/ci-basic-overlay.sh
@@ -0,0 +1,103 @@
+#!/usr/bin/env bash
+
+# This is the basic overlay set for repositories in the CI.
+
+# Maybe we should just use Ruby to have real objects...
+
+########################################################################
+# MathComp
+########################################################################
+: ${mathcomp_CI_BRANCH:=master}
+: ${mathcomp_CI_GITURL:=https://github.com/math-comp/math-comp.git}
+
+########################################################################
+# UniMath
+########################################################################
+: ${UniMath_CI_BRANCH:=master}
+: ${UniMath_CI_GITURL:=https://github.com/UniMath/UniMath.git}
+
+########################################################################
+# Unicoq + Metacoq
+########################################################################
+: ${unicoq_CI_BRANCH:=master}
+: ${unicoq_CI_GITURL:=https://github.com/unicoq/unicoq.git}
+
+: ${metacoq_CI_BRANCH:=master}
+: ${metacoq_CI_GITURL:=https://github.com/MetaCoq/MetaCoq.git}
+
+########################################################################
+# Mathclasses + Corn
+########################################################################
+: ${math_classes_CI_BRANCH:=v8.6}
+: ${math_classes_CI_GITURL:=https://github.com/math-classes/math-classes.git}
+
+: ${Corn_CI_BRANCH:=v8.6}
+: ${Corn_CI_GITURL:=https://github.com/c-corn/corn.git}
+
+########################################################################
+# Iris
+########################################################################
+: ${stdpp_CI_BRANCH:=master}
+: ${stdpp_CI_GITURL:=https://gitlab.mpi-sws.org/robbertkrebbers/coq-stdpp.git}
+
+: ${Iris_CI_BRANCH:=master}
+: ${Iris_CI_GITURL:=https://gitlab.mpi-sws.org/FP/iris-coq.git}
+
+########################################################################
+# HoTT
+########################################################################
+: ${HoTT_CI_BRANCH:=mz-8.7}
+: ${HoTT_CI_GITURL:=https://github.com/ejgallego/HoTT.git}
+
+########################################################################
+# GeoCoq
+########################################################################
+: ${GeoCoq_CI_BRANCH:=master}
+: ${GeoCoq_CI_GITURL:=https://github.com/GeoCoq/GeoCoq.git}
+
+########################################################################
+# Flocq
+########################################################################
+: ${Flocq_CI_BRANCH:=master}
+: ${Flocq_CI_GITURL:=https://scm.gforge.inria.fr/anonscm/git/flocq/flocq.git}
+
+########################################################################
+# Coquelicot
+########################################################################
+: ${Coquelicot_CI_BRANCH:=master}
+: ${Coquelicot_CI_GITURL:=https://scm.gforge.inria.fr/anonscm/git/coquelicot/coquelicot.git}
+
+########################################################################
+# CompCert
+########################################################################
+: ${CompCert_CI_BRANCH:=master}
+: ${CompCert_CI_GITURL:=https://github.com/AbsInt/CompCert.git}
+
+########################################################################
+# fiat_parsers
+########################################################################
+: ${fiat_parsers_CI_BRANCH:=master}
+: ${fiat_parsers_CI_GITURL:=https://github.com/mit-plv/fiat.git}
+
+########################################################################
+# fiat_crypto
+########################################################################
+: ${fiat_crypto_CI_BRANCH:=master}
+: ${fiat_crypto_CI_GITURL:=https://github.com/mit-plv/fiat-crypto.git}
+
+########################################################################
+# CoLoR
+########################################################################
+: ${Color_CI_SVNURL:=https://scm.gforge.inria.fr/anonscm/svn/color/trunk/color}
+
+########################################################################
+# SF
+########################################################################
+: ${sf_CI_TARURL:=https://www.cis.upenn.edu/~bcpierce/sf/current/sf.tgz}
+
+########################################################################
+# TLC
+########################################################################
+: ${tlc_CI_BRANCH:=master}
+: ${tlc_CI_GITURL:=https://gforge.inria.fr/git/tlc/tlc.git}
+
diff --git a/dev/ci/ci-color.sh b/dev/ci/ci-color.sh
index 78ae7f02f..3f0716511 100755
--- a/dev/ci/ci-color.sh
+++ b/dev/ci/ci-color.sh
@@ -1,8 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-svn checkout https://scm.gforge.inria.fr/anonscm/svn/color/trunk/color color
+Color_CI_DIR=${CI_BUILD_DIR}/color
 
-( cd color && make -j ${NJOBS} )
+svn checkout ${Color_CI_SVNURL} ${Color_CI_DIR}
+
+( cd ${Color_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-common.sh b/dev/ci/ci-common.sh
index 412da626f..9fdd2504d 100644
--- a/dev/ci/ci-common.sh
+++ b/dev/ci/ci-common.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 set -xe
 
@@ -8,20 +8,34 @@ export PATH=`pwd`/bin:$PATH
 
 ls `pwd`/bin
 
-# Maybe we should just use Ruby...
-mathcomp_CI_BRANCH=master
-mathcomp_CI_GITURL=https://github.com/math-comp/math-comp.git
+# Where we clone and build external developments
+CI_BUILD_DIR=`pwd`/_build_ci
 
-# git_checkout branch
+source ${ci_dir}/ci-user-overlay.sh
+source ${ci_dir}/ci-basic-overlay.sh
+
+mathcomp_CI_DIR=${CI_BUILD_DIR}/math-comp
+
+# git_checkout branch url dest will create a git repository
+# in <dest> (if it does not exist already) and checkout the
+# remote branch <branch> from <url>
 git_checkout()
 {
   local _BRANCH=${1}
   local _URL=${2}
   local _DEST=${3}
 
-  echo "Checking out ${_DEST}"
-  git clone --depth 1 -b ${_BRANCH} ${_URL} ${_DEST}
-  ( cd ${3} && echo "${_DEST}: `git log -1 --format='%s | %H | %cd | %aN'`" )
+  # Allow an optional 4th argument for the commit
+  local _COMMIT=${4:-FETCH_HEAD}
+  local _DEPTH=${5:-1}
+
+  mkdir -p ${_DEST}
+  ( cd ${_DEST}                                                && \
+    if [ ! -d .git ] ; then git clone --depth ${_DEPTH} ${_URL} . ; fi && \
+    echo "Checking out ${_DEST}"                               && \
+    git fetch ${_URL} ${_BRANCH}                               && \
+    git checkout ${_COMMIT}                                    && \
+    echo "${_DEST}: `git log -1 --format='%s | %H | %cd | %aN'`" )
 }
 
 checkout_mathcomp()
@@ -34,8 +48,8 @@ install_ssreflect()
 {
   echo 'Installing ssreflect' && echo -en 'travis_fold:start:ssr.install\\r'
 
-  checkout_mathcomp math-comp
-  ( cd math-comp/mathcomp            && \
+  checkout_mathcomp ${mathcomp_CI_DIR}
+  ( cd ${mathcomp_CI_DIR}/mathcomp   && \
     sed -i.bak '/ssrtest/d'     Make && \
     sed -i.bak '/odd_order/d'   Make && \
     sed -i.bak '/all\/all.v/d'  Make && \
diff --git a/dev/ci/ci-compcert.sh b/dev/ci/ci-compcert.sh
index ec09389f8..c78ffdc2c 100755
--- a/dev/ci/ci-compcert.sh
+++ b/dev/ci/ci-compcert.sh
@@ -1,13 +1,12 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-CompCert_CI_BRANCH=master
-CompCert_CI_GITURL=https://github.com/AbsInt/CompCert.git
+CompCert_CI_DIR=${CI_BUILD_DIR}/CompCert
 
 opam install -j ${NJOBS} -y menhir
-git_checkout ${CompCert_CI_BRANCH} ${CompCert_CI_GITURL} CompCert
+git_checkout ${CompCert_CI_BRANCH} ${CompCert_CI_GITURL} ${CompCert_CI_DIR}
 
 # Patch to avoid the upper version limit
-( cd CompCert && sed -i.bak 's/8.6)/8.6|trunk)/' configure && ./configure x86_32-linux && make -j ${NJOBS} )
+( cd ${CompCert_CI_DIR} && sed -i.bak 's/8.6)/8.6|trunk)/' configure && ./configure x86_32-linux && make -j ${NJOBS} )
diff --git a/dev/ci/ci-coquelicot.sh b/dev/ci/ci-coquelicot.sh
index 94bd5e468..40eff03b7 100755
--- a/dev/ci/ci-coquelicot.sh
+++ b/dev/ci/ci-coquelicot.sh
@@ -1,12 +1,12 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
+Coquelicot_CI_DIR=${CI_BUILD_DIR}/coquelicot
+
 install_ssreflect
 
-# Setup coquelicot
-git_checkout master https://scm.gforge.inria.fr/anonscm/git/coquelicot/coquelicot.git coquelicot
+git_checkout ${Coquelicot_CI_BRANCH} ${Coquelicot_CI_GITURL} ${Coquelicot_CI_DIR}
 
-( cd coquelicot && ./autogen.sh && ./configure && ./remake -j${NJOBS} )
+( cd ${Coquelicot_CI_DIR} && ./autogen.sh && ./configure && ./remake -j${NJOBS} )
diff --git a/dev/ci/ci-cpdt.sh b/dev/ci/ci-cpdt.sh
index 18d756180..0e791ebbf 100755
--- a/dev/ci/ci-cpdt.sh
+++ b/dev/ci/ci-cpdt.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
diff --git a/dev/ci/ci-fiat-crypto.sh b/dev/ci/ci-fiat-crypto.sh
index c669195dd..93d39aab0 100755
--- a/dev/ci/ci-fiat-crypto.sh
+++ b/dev/ci/ci-fiat-crypto.sh
@@ -1,9 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-git_checkout master https://github.com/mit-plv/fiat-crypto.git fiat-crypto
+fiat_crypto_CI_DIR=${CI_BUILD_DIR}/fiat-crypto
 
-( cd fiat-crypto && make -j ${NJOBS} )
+git_checkout ${fiat_crypto_CI_BRANCH} ${fiat_crypto_CI_GITURL} ${fiat_crypto_CI_DIR}
+
+( cd ${fiat_crypto_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-fiat-parsers.sh b/dev/ci/ci-fiat-parsers.sh
new file mode 100755
index 000000000..c62aa1d85
--- /dev/null
+++ b/dev/ci/ci-fiat-parsers.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+ci_dir="$(dirname "$0")"
+source ${ci_dir}/ci-common.sh
+
+fiat_parsers_CI_DIR=${CI_BUILD_DIR}/fiat
+
+git_checkout ${fiat_parsers_CI_BRANCH} ${fiat_parsers_CI_GITURL} ${fiat_parsers_CI_DIR}
+
+( cd ${fiat_parsers_CI_DIR} && make -j ${NJOBS} parsers )
diff --git a/dev/ci/ci-flocq.sh b/dev/ci/ci-flocq.sh
index 345924e40..ec19bd993 100755
--- a/dev/ci/ci-flocq.sh
+++ b/dev/ci/ci-flocq.sh
@@ -1,9 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-git_checkout master https://scm.gforge.inria.fr/anonscm/git/flocq/flocq.git flocq
+Flocq_CI_DIR=${CI_BUILD_DIR}/flocq
 
-( cd flocq && ./autogen.sh && ./configure && ./remake -j${NJOBS} )
+git_checkout ${Flocq_CI_BRANCH} ${Flocq_CI_GITURL} ${Flocq_CI_DIR}
+
+( cd ${Flocq_CI_DIR} && ./autogen.sh && ./configure && ./remake -j${NJOBS} )
diff --git a/dev/ci/ci-geocoq.sh b/dev/ci/ci-geocoq.sh
index 29667b018..4e5aa2687 100755
--- a/dev/ci/ci-geocoq.sh
+++ b/dev/ci/ci-geocoq.sh
@@ -1,15 +1,13 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-# XXX: replace by generic template
-GeoCoq_CI_BRANCH=master
-GeoCoq_CI_GITURL=https://github.com/GeoCoq/GeoCoq.git
+GeoCoq_CI_DIR=${CI_BUILD_DIR}/GeoCoq
 
-git_checkout ${GeoCoq_CI_BRANCH} ${GeoCoq_CI_GITURL} GeoCoq
+git_checkout ${GeoCoq_CI_BRANCH} ${GeoCoq_CI_GITURL} ${GeoCoq_CI_DIR}
 
-( cd GeoCoq                                               && \
+( cd ${GeoCoq_CI_DIR}                                     && \
   ./configure.sh                                          && \
   sed -i.bak '/Ch16_coordinates_with_functions\.v/d' Make && \
   sed -i.bak '/Elements\/Book_1\.v/d'                Make && \
diff --git a/dev/ci/ci-hott.sh b/dev/ci/ci-hott.sh
index 0c07564c0..1bf6e9a87 100755
--- a/dev/ci/ci-hott.sh
+++ b/dev/ci/ci-hott.sh
@@ -1,8 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-git_checkout mz-8.7 https://github.com/ejgallego/HoTT.git HoTT
+HoTT_CI_DIR=${CI_BUILD_DIR}/HoTT
 
-( cd HoTT && ./autogen.sh && ./configure && make -j ${NJOBS} )
+git_checkout ${HoTT_CI_BRANCH} ${HoTT_CI_GITURL} ${HoTT_CI_DIR}
+
+( cd ${HoTT_CI_DIR} && ./autogen.sh && ./configure && make -j ${NJOBS} )
diff --git a/dev/ci/ci-iris-coq.sh b/dev/ci/ci-iris-coq.sh
index c21af976f..dcb46ed2a 100755
--- a/dev/ci/ci-iris-coq.sh
+++ b/dev/ci/ci-iris-coq.sh
@@ -1,17 +1,27 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
+stdpp_CI_DIR=${CI_BUILD_DIR}/coq-stdpp
+
+Iris_CI_DIR=${CI_BUILD_DIR}/iris-coq
+
 install_ssreflect
 
+# Setup Iris first, as it is needed to compute the dependencies
+
+git_checkout ${Iris_CI_BRANCH} ${Iris_CI_GITURL} ${Iris_CI_DIR}
+read -a IRIS_DEP < ${Iris_CI_DIR}/opam.pins
+
 # Setup stdpp
-git_checkout master https://gitlab.mpi-sws.org/robbertkrebbers/coq-stdpp.git coq-stdpp
+stdpp_CI_GITURL=${IRIS_DEP[1]}.git
+stdpp_CI_COMMIT=${IRIS_DEP[2]}
+stdpp_CI_DEPTH="1000"
 
-( cd coq-stdpp && make -j ${NJOBS} && make install )
+git_checkout ${stdpp_CI_BRANCH} ${stdpp_CI_GITURL} ${stdpp_CI_DIR} ${stdpp_CI_COMMIT} ${stdpp_CI_DEPTH}
 
-# Setup Iris
-git_checkout master https://gitlab.mpi-sws.org/FP/iris-coq.git iris-coq
+( cd ${stdpp_CI_DIR} && make -j ${NJOBS} && make install )
 
-( cd iris-coq && make -j ${NJOBS} )
+# Build iris now
+( cd ${Iris_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-math-classes.sh b/dev/ci/ci-math-classes.sh
index 4450dc071..beb75773b 100755
--- a/dev/ci/ci-math-classes.sh
+++ b/dev/ci/ci-math-classes.sh
@@ -1,12 +1,20 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-git_checkout v8.6 https://github.com/math-classes/math-classes.git math-classes
-( cd math-classes && make -j ${NJOBS} && make install )
+math_classes_CI_DIR=${CI_BUILD_DIR}/math-classes
 
-git_checkout v8.6 https://github.com/c-corn/corn.git corn
-( cd corn         && make -j ${NJOBS} )
+Corn_CI_DIR=${CI_BUILD_DIR}/corn
 
+# Setup Math-Classes
+
+git_checkout ${math_classes_CI_BRANCH} ${math_classes_CI_GITURL} ${math_classes_CI_DIR}
+
+( cd ${math_classes_CI_DIR} && make -j ${NJOBS} && make install )
+
+# Setup Corn
+
+git_checkout ${Corn_CI_BRANCH} ${Corn_CI_GITURL} ${Corn_CI_DIR}
+
+( cd ${Corn_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-math-comp.sh b/dev/ci/ci-math-comp.sh
index 2eb150cb5..bb8188da4 100755
--- a/dev/ci/ci-math-comp.sh
+++ b/dev/ci/ci-math-comp.sh
@@ -1,13 +1,15 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-checkout_mathcomp math-comp
+mathcomp_CI_DIR=${CI_BUILD_DIR}/math-comp
+
+checkout_mathcomp ${mathcomp_CI_DIR}
 
 # odd_order takes too much time for travis.
-( cd math-comp/mathcomp                           && \
+( cd ${mathcomp_CI_DIR}/mathcomp                  && \
   sed -i.bak '/PFsection/d'                  Make && \
   sed -i.bak '/stripped_odd_order_theorem/d' Make && \
   make Makefile.coq && make -f Makefile.coq -j ${NJOBS} all )
diff --git a/dev/ci/ci-metacoq.sh b/dev/ci/ci-metacoq.sh
index 91a33695b..e31691179 100755
--- a/dev/ci/ci-metacoq.sh
+++ b/dev/ci/ci-metacoq.sh
@@ -1,16 +1,19 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
-# $0 is not the safest way, but...
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-# MetaCoq + UniCoq
+unicoq_CI_DIR=${CI_BUILD_DIR}/unicoq
+metacoq_CI_DIR=${CI_BUILD_DIR}/MetaCoq
 
-git_checkout master https://github.com/unicoq/unicoq.git unicoq
+# Setup UniCoq
 
-( cd unicoq && coq_makefile -f Make -o Makefile && make -j ${NJOBS} && make install )
+git_checkout ${unicoq_CI_BRANCH} ${unicoq_CI_GITURL} ${unicoq_CI_DIR}
 
-git_checkout master https://github.com/MetaCoq/MetaCoq.git MetaCoq
+( cd ${unicoq_CI_DIR} && coq_makefile -f Make -o Makefile && make -j ${NJOBS} && make install )
 
-( cd MetaCoq && coq_makefile -f _CoqProject -o Makefile && make -j ${NJOBS} )
+# Setup MetaCoq
 
+git_checkout ${metacoq_CI_BRANCH} ${metacoq_CI_GITURL} ${metacoq_CI_DIR}
+
+( cd ${metacoq_CI_DIR} && coq_makefile -f _CoqProject -o Makefile && make -j ${NJOBS} )
diff --git a/dev/ci/ci-sf.sh b/dev/ci/ci-sf.sh
index 5e41211f1..7d23ccad9 100755
--- a/dev/ci/ci-sf.sh
+++ b/dev/ci/ci-sf.sh
@@ -1,9 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-wget https://www.cis.upenn.edu/~bcpierce/sf/current/sf.tgz
+# XXX: Needs fixing to properly set the build directory.
+wget ${sf_CI_TARURL}
 tar xvfz sf.tgz
 
 ( cd sf && sed -i.bak 's/(K,N)/((K,N))/' LibTactics.v && make clean && make -j ${NJOBS} )
diff --git a/dev/ci/ci-template.sh b/dev/ci/ci-template.sh
new file mode 100755
index 000000000..700105aed
--- /dev/null
+++ b/dev/ci/ci-template.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+ci_dir="$(dirname "$0")"
+source ${ci_dir}/ci-common.sh
+
+Template_CI_BRANCH=master
+Template_CI_GITURL=https://github.com/Template/Template
+Template_CI_DIR=${CI_BUILD_DIR}/Template
+
+git_checkout ${Template_CI_BRANCH} ${Template_CI_GITURL} ${Template_CI_DIR}
+
+( cd ${Template_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-tlc.sh b/dev/ci/ci-tlc.sh
index b94632492..ce2639937 100755
--- a/dev/ci/ci-tlc.sh
+++ b/dev/ci/ci-tlc.sh
@@ -1,8 +1,10 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-git_checkout master https://gforge.inria.fr/git/tlc/tlc.git tlc
+tlc_CI_DIR=${CI_BUILD_DIR}/tlc
 
-( cd tlc && make -j ${NJOBS} )
+git_checkout ${tlc_CI_BRANCH} ${tlc_CI_GITURL} ${tlc_CI_DIR}
+
+( cd ${tlc_CI_DIR} && make -j ${NJOBS} )
diff --git a/dev/ci/ci-unimath.sh b/dev/ci/ci-unimath.sh
index 15e619acb..175b82b5f 100755
--- a/dev/ci/ci-unimath.sh
+++ b/dev/ci/ci-unimath.sh
@@ -1,14 +1,13 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 ci_dir="$(dirname "$0")"
 source ${ci_dir}/ci-common.sh
 
-UniMath_CI_BRANCH=master
-UniMath_CI_GITURL=https://github.com/UniMath/UniMath.git
+UniMath_CI_DIR=${CI_BUILD_DIR}/UniMath
 
-git_checkout ${UniMath_CI_BRANCH} ${UniMath_CI_GITURL} UniMath
+git_checkout ${UniMath_CI_BRANCH} ${UniMath_CI_GITURL} ${UniMath_CI_DIR}
 
-( cd UniMath                                  && \
+( cd ${UniMath_CI_DIR}                        && \
   sed -i.bak '/Folds/d'              Makefile && \
   sed -i.bak '/HomologicalAlgebra/d' Makefile && \
   make -j ${NJOBS} BUILD_COQ=no )
diff --git a/dev/ci/ci-user-overlay.sh b/dev/ci/ci-user-overlay.sh
new file mode 100644
index 000000000..028574743
--- /dev/null
+++ b/dev/ci/ci-user-overlay.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+# Add user overlays here. You can use some logic to detect if you are
+# in your travis branch and conditionally enable the overlay.
+
+# Some useful Travis variables:
+# (https://docs.travis-ci.com/user/environment-variables/#Default-Environment-Variables)
+#
+# - TRAVIS_BRANCH: For builds not triggered by a pull request this is
+#   the name of the branch currently being built; whereas for builds
+#   triggered by a pull request this is the name of the branch
+#   targeted by the pull request (in many cases this will be master).
+#
+# - TRAVIS_COMMIT: The commit that the current build is testing.
+#
+# - TRAVIS_PULL_REQUEST: The pull request number if the current job is
+#   a pull request, “false” if it’s not a pull request.
+#
+# - TRAVIS_PULL_REQUEST_BRANCH: If the current job is a pull request,
+#   the name of the branch from which the PR originated. "" if the
+#   current job is a push build.
+