diff --git a/doc/abi-check.in b/doc/abi-check.in
index 168ab0c42b..5a5e253f74 100755
--- a/doc/abi-check.in
+++ b/doc/abi-check.in
@@ -1,140 +1,158 @@
 #!@BASH_PATH@
+#
+# Copyright 2011-2022 the Pacemaker project contributors
+#
+# The version control history for this file may have further details.
+#
+# This source code is licensed under the GNU General Public License version 2
+# or later (GPLv2+) WITHOUT ANY WARRANTY.
+#
+
 #
 # abi-check [-u] <package-name> <version> [...]
 #
 # Build ABI dumps for all listed versions. If exactly two are given,
 # build an ABI compatibility report for them, and if -u is given,
 # upload it to the website.
 #
 
 # Top-level rsync destination for www targets (without trailing slash)
 : ${RSYNC_DEST:=root@www.clusterlabs.org:/var/www/html}
 
 # If the argument is of form x.y.z, print Pacemaker-x.y.z,
 # otherwise print the argument (presumably a commit ID) directly
 tag() {
     if [[ "$1" =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3} ]]; then
         echo "Pacemaker-$1"
     else
         echo "$1"
     fi
 }
 
 # Strip anything up to and including a dash from the argument
 version() {
     echo "$1" | sed s:.*-::
 }
 
 # Create configuration file for ABI dumper
 abi_config() {
     PACKAGE="$1"
     VERSION="$2"
     BUILD_ROOT="$3"
     DESC="$4"
 
     # Create header
     DESC="$BUILD_ROOT/$VERSION.xml"
     cat <<EOF > "$DESC"
 <?xml version="1.0" encoding="utf-8"?>
 <descriptor>
 <version>
     $VERSION
 </version>
 <headers>
         $BUILD_ROOT/root/usr/include/$PACKAGE/crm
 </headers>
 <libs>
 EOF
 
     # Build checkout, installing into subdirectory
     ( cd "$BUILD_ROOT" && ./autogen.sh && ./configure --disable-fatal-warnings )
     make -C "$BUILD_ROOT" V=0 DESTDIR="${BUILD_ROOT}/root" install
     if [ $? -ne 0 ]; then
         echo "Build for $TAG failed. Repair, populate <libs/> and re-run: "
         echo "  abi-compliance-checker -l $PACKAGE -dump_abi $DESC"
         echo ""
         echo "To find libraries after building:"
         echo "  find $BUILD_ROOT/root -name "*.so" -print"
         exit 1
     fi
 
     # Add library names to configuration file
     find $BUILD_ROOT/root -name "*.so" -print >> $DESC
 
     # Add footer
     cat <<EOF >> "$DESC"
 </libs>
 </descriptor>
 EOF
 }
 
 # Dump the ABI for a particular version
 extract_one() {
     TAG="$1"
     VERSION="$2"
 
     # If dump already exists, remove it if dumping HEAD (which changes),
     # otherwise use it (a dump for a particular commit stays the same).
     TARBALL="abi_dumps/$PACKAGE/${PACKAGE}_$VERSION.abi.tar.gz"
     if [ "$VERSION" = HEAD ]; then
         rm -rf "$TARBALL"
     elif [ -f "$TARBALL" ]; then
         return
     fi
 
     echo "Building ABI dump for $*"
 
     # Get a clean checkout at the desired commit
     BUILD_ROOT=".ABI-build"
     rm -rf "$BUILD_ROOT"
     ( cd .. ; git archive --prefix "doc/$BUILD_ROOT/" "$TAG" | tar xv )
     if [ $? -ne 0 ]; then
         exit
     fi
 
     # Remove "doc" from SUBDIRS in Makefile (but why?)
     BUILD_ROOT="$(pwd)/$BUILD_ROOT"
     sed -i.sed 's: doc::' "$BUILD_ROOT/Makefile.am"
 
     # Run ABI dump
     abi_config "$PACKAGE" "$VERSION" "$BUILD_ROOT" "$DESC"
     abi-compliance-checker -l "$PACKAGE" -dump_abi "$DESC" \
         -dump-path "abi_dumps/${PACKAGE}/${PACKAGE}_${VERSION}.abi.tar.gz"
 
     # Clean up
     rm -rf "$BUILD_ROOT"
 }
 
 extract_all() {
     for arg in $*; do
         T=$(tag "$arg")
         V=$(version "$T")
         extract_one "$T" "$V"
     done
 }
 
+die() {
+	echo "$@" 1>&2
+	exit 1
+}
+
+which git 2>/dev/null || die "abi-check: git must be installed"
+git rev-parse --git-dir >/dev/null 2>/dev/null	\
+	|| die "abi-check: must be run from git checkout"
+
 UPLOAD=0
 if [ "$1" = "-u" ]; then
     UPLOAD=1; shift
 fi
 
 PACKAGE="$1"; shift
 
 extract_all "$@"
 
 if [ $# -eq 2 ]; then
     V1=$(version "$1")
     V2=$(version "$2")
 
     abi-compliance-checker -l ${PACKAGE} \
         -d1 abi_dumps/${PACKAGE}/${PACKAGE}_${V1}.abi.tar.gz \
         -d2 abi_dumps/${PACKAGE}/${PACKAGE}_${V2}.abi.tar.gz
     if [ $? -ne 0 ]; then
         echo "WARNING: compliance checker exited $?"
     fi
 
     COMPAT_REPORT="compat_reports/${PACKAGE}/${V1}_to_${V2}"
     if [ $UPLOAD -eq 1 ] && [ -d "$COMPAT_REPORT" ]; then
         rsync -azxlSD --progress "$COMPAT_REPORT" "${RSYNC_DEST}/${PACKAGE}/abi/"
     fi
 fi