CI: test that opam install works

.github/workflows/workflow.yml

@@ -53,6 +53,8 @@ jobs:
 
       - run: opam exec -- make all
 
+      - run: opam install .
+
   # lint-doc:
   #   runs-on: ubuntu-latest
   #   steps:

Makefile

@@ -46,11 +46,17 @@ distclean: clean.local
 # BB different, make files universally accessible, we cannot chown.
 INSTALL_CAN_PUT_PERMISSIONS=yes
 INSTALL_USER_GROUP=-o $(OCSIGENUSER) -g "$(OCSIGENGROUP)"
-INSTALL_MOD_660=660
-INSTALL_MOD_644=644
-INSTALL_MOD_755=755
-INSTALL_MOD_770=770
-INSTALL_MOD_750=750
+INSTALL_MOD_660=-m 660
+INSTALL_MOD_644=-m 644
+INSTALL_MOD_755=-m 755
+INSTALL_MOD_770=-m 770
+INSTALL_MOD_750=-m 750
+INSTALL_DIR=$(INSTALL) -d
+INSTALL_FILE=$(INSTALL)
+# The Unix permission/ownership handling below is meaningless on Windows (the
+# OCSIGEN_WINDOWS branch drops modes and ownership anyway), and OCSIGENGROUP is
+# empty there, which makes the `grep` check below print a usage error. Skip it.
+ifneq ($(OCSIGEN_WINDOWS), yes)
 USERNAME=$(shell whoami)
 ifneq ($(shell id -u), 0)
   ifneq ($(OCSIGENUSER), $(USERNAME))
@@ -62,38 +68,54 @@ ifneq ($(shell id -u), 0)
 endif
 ifeq ($(INSTALL_CAN_PUT_PERMISSIONS), no)
     INSTALL_USER_GROUP=
-    INSTALL_MOD_660=666
-    INSTALL_MOD_644=666
-    INSTALL_MOD_755=777
-    INSTALL_MOD_770=777
-    INSTALL_MOD_750=777
+    INSTALL_MOD_660=-m 666
+    INSTALL_MOD_644=-m 666
+    INSTALL_MOD_755=-m 777
+    INSTALL_MOD_770=-m 777
+    INSTALL_MOD_750=-m 777
+endif
+endif
+
+# On Windows (Cygwin), NTFS does not support Unix permission bits and `install`
+# aborts when it fails to chmod the freshly created file or directory. Fall back
+# to plain `mkdir -p` / `cp` and drop the mode and ownership flags.
+# OCSIGEN_WINDOWS is set by ./configure (see Makefile.config).
+ifeq ($(OCSIGEN_WINDOWS), yes)
+    INSTALL_USER_GROUP=
+    INSTALL_MOD_660=
+    INSTALL_MOD_644=
+    INSTALL_MOD_755=
+    INSTALL_MOD_770=
+    INSTALL_MOD_750=
+    INSTALL_DIR=mkdir -p
+    INSTALL_FILE=cp
 endif
 
 install.files:
 	@echo
 	@echo INSTALL_CAN_PUT_PERMISSIONS: ${INSTALL_CAN_PUT_PERMISSIONS}
 	 ## Configuration files
-	$(INSTALL) -m ${INSTALL_MOD_755} -d $(TEMPROOT)$(CONFIGDIR)/conf.d
-	${INSTALL} -m ${INSTALL_MOD_644} _build/install/default/etc/ocsigenserver/ocsigenserver.conf.sample $(TEMPROOT)$(CONFIGDIR)/
+	$(INSTALL_DIR) ${INSTALL_MOD_755} $(TEMPROOT)$(CONFIGDIR)/conf.d
+	$(INSTALL_FILE) ${INSTALL_MOD_644} _build/install/default/etc/ocsigenserver/ocsigenserver.conf.sample $(TEMPROOT)$(CONFIGDIR)/
 	[ -f $(TEMPROOT)$(CONFIGDIR)/ocsigenserver.conf ] || \
-	  { $(INSTALL) -m ${INSTALL_MOD_644} _build/install/default/etc/ocsigenserver/ocsigenserver.conf.sample \
+	  { $(INSTALL_FILE) ${INSTALL_MOD_644} _build/install/default/etc/ocsigenserver/ocsigenserver.conf.sample \
 		$(TEMPROOT)$(CONFIGDIR)/ocsigenserver.conf;  }
 	-mv $(TEMPROOT)$(CONFIGDIR)/mime.types $(TEMPROOT)$(CONFIGDIR)/mime.types.old
 	 ## Log directory
-	$(INSTALL) -m ${INSTALL_MOD_644} src/files/mime.types $(TEMPROOT)$(CONFIGDIR)
-	$(INSTALL) -d -m ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} $(TEMPROOT)$(LOGDIR)
+	$(INSTALL_FILE) ${INSTALL_MOD_644} src/files/mime.types $(TEMPROOT)$(CONFIGDIR)
+	$(INSTALL_DIR) ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} $(TEMPROOT)$(LOGDIR)
 	 ## Static files
-	$(INSTALL) -d -m ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} $(TEMPROOT)$(STATICPAGESDIR)
-	$(INSTALL) -d -m ${INSTALL_MOD_750} ${INSTALL_USER_GROUP} $(TEMPROOT)$(DATADIR)
-	$(INSTALL) -m ${INSTALL_MOD_644} ${INSTALL_USER_GROUP} \
+	$(INSTALL_DIR) ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} $(TEMPROOT)$(STATICPAGESDIR)
+	$(INSTALL_DIR) ${INSTALL_MOD_750} ${INSTALL_USER_GROUP} $(TEMPROOT)$(DATADIR)
+	$(INSTALL_FILE) ${INSTALL_MOD_644} ${INSTALL_USER_GROUP} \
 	  local/var/www/*.html $(TEMPROOT)$(STATICPAGESDIR)
-	$(INSTALL) -d -m ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} \
+	$(INSTALL_DIR) ${INSTALL_MOD_755} ${INSTALL_USER_GROUP} \
 	  $(TEMPROOT)$(STATICPAGESDIR)/ocsigenstuff
-	$(INSTALL) -m ${INSTALL_MOD_644} ${INSTALL_USER_GROUP} \
+	$(INSTALL_FILE) ${INSTALL_MOD_644} ${INSTALL_USER_GROUP} \
 	  local/var/www/ocsigenstuff/*.png local/var/www/ocsigenstuff/*.css \
 	  $(TEMPROOT)$(STATICPAGESDIR)/ocsigenstuff
 	mkdir -p $(TEMPROOT)$(MANDIR)
-	$(INSTALL) -m ${INSTALL_MOD_644} src/files/ocsigenserver.1 $(TEMPROOT)$(MANDIR)
+	$(INSTALL_FILE) ${INSTALL_MOD_644} src/files/ocsigenserver.1 $(TEMPROOT)$(MANDIR)
 
 uninstall:
 	-rm -f $(TEMPROOT)$(CONFIGDIR)/ocsigenserver.conf.sample

configure

@@ -343,6 +343,32 @@ while [ "$#" -gt 0 ]; do
 	esac
 done
 
+# Detect a Cygwin/Windows build. cygpath is only available on Cygwin, so its
+# presence both identifies the platform and provides the path conversion we
+# need: on Windows opam passes Windows-style paths (backslash separators, drive
+# letters, and occasionally a stray double quote from an empty argument such as
+# `--temproot ""`). The Cygwin shell that runs the install recipes would eat the
+# backslashes as escape characters, so normalize every path through cygpath into
+# a form it accepts (e.g. D:/a/...). On Unix cygpath is absent and paths are
+# left untouched.
+if command -v cygpath >/dev/null 2>&1; then
+  windows=yes
+else
+  windows=no
+fi
+
+if [ "$windows" = yes ]; then
+  for __var in prefix root temproot bindir logdir libdir mandir docdir \
+               commandpipe sysconfdir staticpagesdir uploaddir datadir full_pwd; do
+    eval "__val=\$$__var"
+    __val=`printf '%s' "$__val" | tr -d '"'`
+    if [ -n "$__val" ]; then
+      __val=`cygpath -m "$__val" 2>/dev/null || printf '%s' "$__val"`
+    fi
+    eval "$__var=\$__val"
+  done
+fi
+
 case "$bindir" in
   "") bindir="$prefix/bin";;
 esac
@@ -476,6 +502,10 @@ ocamlinclude=`ocamlfind printconf stdlib`
 echo "Writing Makefile.config"
 cat <<_EOF_ > $my_pwd/Makefile.config
 
+# Whether this is a Cygwin/Windows build (NTFS cannot apply Unix permissions, so
+# install.files falls back to mkdir -p / cp instead of install -m).
+OCSIGEN_WINDOWS := $windows
+
 #### External binaries ####
 
 OCAMLFIND := ocamlfind

ocsigenserver.opam

@@ -36,7 +36,6 @@ conflicts: [
 ]
 dev-repo: "git+https://github.com/ocsigen/ocsigenserver.git"
 x-maintenance-intent: ["(latest)"]
-available: os != "win32"
 build: [
   [
     "sh"

ocsigenserver.opam.template

@@ -1,4 +1,3 @@
-available: os != "win32"
 build: [
   [
     "sh"