$NetBSD$

Work around core dump when building documentation.

--- doc/Makefile.in.orig	2024-04-23 23:27:26.000000000 +0000
+++ doc/Makefile.in
@@ -12,8 +12,8 @@ MANPAGES = gosh.1 gauche-config.1 gauche
 EXTRACTED = gauche-refe.texi gauche-refj.texi \
 	    gauche-deve.texi gauche-devj.texi
 CONFIG_GENERATED = Makefile $(MANPAGES)
-@CROSS_COMPILING_no@GOSH = $(top_builddir)/src/gosh -q -ftest
-@CROSS_COMPILING_yes@GOSH = $(BUILD_GOSH) -q
+@CROSS_COMPILING_no@GOSH = env $(top_builddir)/src/gosh -q -ftest
+@CROSS_COMPILING_yes@GOSH = env $(BUILD_GOSH) -q
 INSTALL      = @INSTALL@
 INSTALL_DATA = @INSTALL_DATA@
 INSTALL_INFO = @INSTALL_INFO@