4 files changed, 21 insertions, 19 deletions
diff --git a/dev/ci/ci-basic-overlay.sh b/dev/ci/ci-basic-overlay.sh
index be819616e2..b65430aa51 100755
--- a/dev/ci/ci-basic-overlay.sh
+++ b/dev/ci/ci-basic-overlay.sh
@@ -8,7 +8,7 @@ declare -a projects # the list of project repos that can be be overlayed
 # checks if the given argument is a known project
 function is_in_projects {
     local rc=1
-    for x in ${!projects[@]}; do
+    for x in ${projects[@]}; do
       if [ "$1" = "$x" ]; then rc=0; fi;
     done
     return rc
@@ -132,7 +132,7 @@ project gappa_tool "https://gitlab.inria.fr/gappa/gappa" "master"
 ########################################################################
 # Gappa plugin
 ########################################################################
-project gappa_plugin "https://gitlab.inria.fr/gappa/coq" "master"
+project gappa "https://gitlab.inria.fr/gappa/coq" "master"
 
 ########################################################################
 # CompCert
@@ -214,7 +214,7 @@ project equations "https://github.com/mattam82/Coq-Equations" "master"
 ########################################################################
 project elpi "https://github.com/LPCIC/coq-elpi" "coq-master"
 
-project elpi_hb "https://github.com/math-comp/hierarchy-builder" "coq-master"
+project hierarchy_builder "https://github.com/math-comp/hierarchy-builder" "coq-master"
 
 ########################################################################
 # Engine-Bench
diff --git a/dev/ci/ci-elpi.sh b/dev/ci/ci-elpi.sh
index 4f185db813..d8caf8ee87 100755
--- a/dev/ci/ci-elpi.sh
+++ b/dev/ci/ci-elpi.sh
@@ -7,6 +7,6 @@ git_download elpi
 
 ( cd "${CI_BUILD_DIR}/elpi" && make && make install )
 
-git_download elpi_hb
+git_download hierarchy_builder
 
-( cd "${CI_BUILD_DIR}/elpi_hb" && make && make install )
+( cd "${CI_BUILD_DIR}/hierarchy_builder" && make && make install )
diff --git a/dev/ci/ci-gappa.sh b/dev/ci/ci-gappa.sh
index c346354b70..1af37aa7c1 100755
--- a/dev/ci/ci-gappa.sh
+++ b/dev/ci/ci-gappa.sh
@@ -7,6 +7,6 @@ git_download gappa_tool
 
 ( cd "${CI_BUILD_DIR}/gappa_tool" && ( if [ ! -x ./configure ]; then autoreconf && touch stamp-config_h.in && ./configure --prefix=${CI_INSTALL_DIR}; fi ) && ./remake "-j${NJOBS}" && ./remake install )
 
-git_download gappa_plugin
+git_download gappa
 
-( cd "${CI_BUILD_DIR}/gappa_plugin" && ( if [ ! -x ./configure ]; then autoconf && ./configure; fi ) && ./remake "-j${NJOBS}" && ./remake install )
+( cd "${CI_BUILD_DIR}/gappa" && ( if [ ! -x ./configure ]; then autoconf && ./configure; fi ) && ./remake "-j${NJOBS}" && ./remake install )
diff --git a/dev/ci/user-overlays/README.md b/dev/ci/user-overlays/README.md
index 14ee5e4199..cf1d71c1cd 100644
--- a/dev/ci/user-overlays/README.md
+++ b/dev/ci/user-overlays/README.md
@@ -5,27 +5,29 @@ have prepared a branch with the fix, you can add an "overlay" to your pull
 request to test it with the adapted version of the external project.
 
 An overlay is a file which defines where to look for the patched
-version so that testing is possible. This is done by calling the
-`overlay` command for each project with the project name (as used in
-the variables in [`ci-basic-overlay.sh`](../ci-basic-overlay.sh)), the
-location of your fork and the branch containing the patch on your
-fork.
-
-Moreover, the file contains very simple logic to test the pull request number
-or branch name and apply it only in this case.
-
+version so that testing is possible.
 The name of your overlay file should start with a five-digit pull request
 number, followed by a dash, anything (for instance your GitHub nickname
 and the branch name), then a `.sh` extension (`[0-9]{5}-[a-zA-Z0-9-_]+.sh`).
 
-Example: `13128-SkySkimmer-noinstance.sh` containing
+This file must contain one or more invocation of the `overlay` function:
+```
+overlay <project> <giturl> <ref> <prnumber> [<prbranch>]
+```
+Each call creates an overlay for `project` using a given `giturl` and
+`ref` which is active for `prnumber` or `prbranch` (`prbranch` defaults
+to `ref`).
 
+Example of an overlay for the project `elpi` that uses the branch `noinstance`
+from the fork of `SkySkimmer` and is active for pull request `13128`
 ```
 overlay elpi https://github.com/SkySkimmer/coq-elpi noinstance 13128
 ```
 
-See [`ci-common.sh`](../ci-common.sh) for the detailed documentation of
-the `overlay` function.
+Such a file can be created automatically using the scripts
+[`create_overlays.sh`](../../dev/tools/create_overlays.sh).
+See also the list of projects for which one can write an overlay in
+the file [`ci-basic-overlay.sh`](../ci-basic-overlay.sh).
 
 ### Branching conventions