Report known error when tcl_ext_lib cannot be loaded

Makefile

@@ -79,7 +79,8 @@ TEST_PREREQ += lib/libtestutil-closedir$(SHLIB_SUFFIX) \
 	lib/libtestutil-0getgroups$(SHLIB_SUFFIX) \
 	lib/libtestutil-dupgetgroups$(SHLIB_SUFFIX) \
 	lib/libtestutil-time$(SHLIB_SUFFIX) \
-	lib/libtestutil-mktime$(SHLIB_SUFFIX)
+	lib/libtestutil-mktime$(SHLIB_SUFFIX) \
+	lib/libtestutil-tcl_loadfile$(SHLIB_SUFFIX)
 endif
 endif
 
@@ -660,6 +661,9 @@ lib/libtestutil-time$(SHLIB_SUFFIX):
 lib/libtestutil-mktime$(SHLIB_SUFFIX):
 	$(MAKE) --no-print-directory -C lib $(@F)
 
+lib/libtestutil-tcl_loadfile$(SHLIB_SUFFIX):
+	$(MAKE) --no-print-directory -C lib $(@F)
+
 # example configs for test rules
 testsuite/example/.modulespath: testsuite/example/.modulespath.in
 	$(translate-in-script)
@@ -1172,6 +1176,7 @@ $(V).SILENT: initdir pkgdoc doc version.inc share/rpm/environment-modules.spec \
 	lib/libtestutil-getpwuid$(SHLIB_SUFFIX) lib/libtestutil-getgroups$(SHLIB_SUFFIX) \
 	lib/libtestutil-0getgroups$(SHLIB_SUFFIX) lib/libtestutil-mktime$(SHLIB_SUFFIX) \
 	lib/libtestutil-dupgetgroups$(SHLIB_SUFFIX) lib/libtestutil-time$(SHLIB_SUFFIX) \
+	lib/libtestutil-tcl_loadfile$(SHLIB_SUFFIX) \
 	testsuite/example/.modulespath testsuite/example/modulespath-wild \
 	testsuite/example/modulerc testsuite/example/initrc-1 testsuite/example/initrc \
 	dist-tar dist-gzip dist-bzip2 dist-win $(MODULECMDTEST) $(MODULECMDTEST)_i

NEWS.rst

@@ -130,6 +130,8 @@ Modules 5.7.0 (not yet released)
   or :subcmd:`sh-to-mod` sub-command, does not get access to shell aliases,
   functions or completions settings only available in interactive sessions or
   defined in profile files. (fix issue #646)
+* Report a global known error when Modules Tcl extension library cannot be
+  loaded. (fix issue #644)
 
 
 .. _5.6 release notes:

lib/.gitignore

@@ -16,6 +16,7 @@
 /libtestutil-dupgetgroups.so
 /libtestutil-time.so
 /libtestutil-mktime.so
+/libtestutil-tcl_loadfile.so
 /envmodules.c.gcov
 /envmodules.gcda
 /envmodules.gcno

lib/Makefile.in

@@ -60,6 +60,10 @@ libtestutil-mktime@SHLIB_SUFFIX@: testutil-mktime.c
 	$(ECHO_CC)
 	$(LDCC) $< -o $@
 
+libtestutil-tcl_loadfile@SHLIB_SUFFIX@: testutil-tcl_loadfile.c
+	$(ECHO_CC)
+	$(LDCC) $< -o $@
+
 clean:
 	rm -f envmodules.o
 	rm -f libtclenvmodules@TCL_SHLIB_SUFFIX@
@@ -70,6 +74,7 @@ clean:
 	rm -f libtestutil-dupgetgroups@SHLIB_SUFFIX@
 	rm -f libtestutil-time@SHLIB_SUFFIX@
 	rm -f libtestutil-mktime@SHLIB_SUFFIX@
+	rm -f libtestutil-tcl_loadfile@SHLIB_SUFFIX@
 	rm -f envmodules.c.gcov envmodules.gcda envmodules.gcno
 
 distclean: clean
@@ -95,4 +100,4 @@ $(V).SILENT: envmodules.o libtclenvmodules@TCL_SHLIB_SUFFIX@ \
 	libtestutil-closedir@SHLIB_SUFFIX@ libtestutil-getpwuid@SHLIB_SUFFIX@ \
 	libtestutil-getgroups@SHLIB_SUFFIX@ libtestutil-0getgroups@SHLIB_SUFFIX@ \
 	libtestutil-dupgetgroups@SHLIB_SUFFIX@ libtestutil-time@SHLIB_SUFFIX@ \
-	libtestutil-mktime@SHLIB_SUFFIX@
+	libtestutil-mktime@SHLIB_SUFFIX@ libtestutil-tcl_loadfile@SHLIB_SUFFIX@

lib/testutil-tcl_loadfile.c

@@ -0,0 +1,35 @@
+/*************************************************************************
+ *
+ * TESTUTIL-TCL_LOADFILE.C, Superseded Tcl_LoadFile function for test purpose
+ * Copyright (C) 2026 Xavier Delaruelle
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ************************************************************************/
+
+#include <tcl.h>
+
+#if !defined (__APPLE__)
+
+int Tcl_LoadFile(Tcl_Interp *interp, Tcl_Obj *pathPtr,
+   const char *const symbols[], int flags, void *procVPtrs,
+   Tcl_LoadHandle *handlePtr)
+{
+   Tcl_SetObjResult(interp, Tcl_ObjPrintf("error message"));
+   return TCL_ERROR;
+}
+
+#endif
+
+/* vim:set tabstop=3 shiftwidth=3 expandtab autoindent: */

tcl/main.tcl.in

@@ -625,7 +625,11 @@ if {[catch {
    ##nagelfar ignore +2 Too long line
    @libtclenvmodules@if {[file readable [getConf tcl_ext_lib]]} {
    @libtclenvmodules@   reportDebug "Load Tcl extension library ([getConf tcl_ext_lib])"
-   @libtclenvmodules@   load [file normalize [getConf tcl_ext_lib]] Envmodules
+   @libtclenvmodules@   if {[catch {
+   @libtclenvmodules@      load [file normalize [getConf tcl_ext_lib]] Envmodules
+   @libtclenvmodules@   } errMsg]} {
+   @libtclenvmodules@      reportErrorAndExit $errMsg
+   @libtclenvmodules@   }
    @libtclenvmodules@   setState tcl_ext_lib_loaded 1
    @libtclenvmodules@}
    # use fallback procs if extension library is not loaded

testsuite/modules.00-init/005-init_ts.exp

@@ -168,6 +168,7 @@ if {$install_libtclenvmodules eq {y}} {
     set dupgetgroupslib_file lib/libtestutil-dupgetgroups$install_shlib_suffix
     set timelib_file lib/libtestutil-time$install_shlib_suffix
     set mktimelib_file lib/libtestutil-mktime$install_shlib_suffix
+    set tcl_loadfilelib_file lib/libtestutil-tcl_loadfile$install_shlib_suffix
 }
 
 # check file permission capabilities

testsuite/modules.00-init/150-access-init.exp

@@ -75,7 +75,7 @@ if {[info exists tclextlib_file]} {
     } else {
         set tserr "$error_msgs: couldn't load file \"$tclextlib_file_abs_re\":.*"
     }
-    testouterr_cmd_re sh {-V} {} $tserr
+    testouterr_cmd_re sh {-V} ERR $tserr
     file delete $tclextlib_file
     file rename $tclextlib_file.orig $tclextlib_file
 }

testsuite/modules.00-init/190-tcl_ext_lib.exp

@@ -0,0 +1,44 @@
+##############################################################################
+#   Modules Revision 3.0
+#   Providing a flexible user environment
+#
+#   File:		modules.00-init/%M%
+#   Revision:		%I%
+#   First Edition:	2026/07/17
+#   Last Mod.:		%U%, %G%
+#
+#   Authors:		Xavier Delaruelle, xavier.delaruelle@cea.fr
+#
+#   Description:	Testuite testsequence
+#   Command:		load
+#   Modulefiles:    bar, foo
+#   Sub-Command:
+#
+#   Comment: %C{
+#         Test Modules Tcl extended library
+#   }C%
+#
+##############################################################################
+
+skip_if_quick_mode
+
+# test error report when loading library
+# ensure we are in a specific test mode so we can play with installed files
+# no need to specifically test on Darwin system and on Tcl < 9
+if {[siteconfig_isStderrTty] && $tcl_platform(os) ne "Darwin" &&\
+    [info exists tclextlib_file] && [info exists tcl_loadfilelib_file] &&\
+    [file exists $tcl_loadfilelib_file] && [cmpversion $tclsh_version 9.0] > -1} {
+    setenv_var LD_PRELOAD $tcl_loadfilelib_file
+
+    set tserr "$error_msgs: error message"
+    testouterr_cmd sh {-V} ERR $tserr
+
+    unsetenv_var LD_PRELOAD
+}
+
+
+#
+#  Cleanup
+#
+
+reset_test_env