Don't install libcomModuleDirs.pm

It's only needed by bldEnvData.pl which is never installed.
Make it a dependency so it gets built, and use it from O.<host>

src/Makefile

@@ -20,8 +20,6 @@ INC += valgrind/valgrind.h
 INC += libComVersion.h
 INC += libComVersionNum.h
 
-PERL_MODULES += libcomModuleDirs.pm
-
 include $(LIBCOM)/as/Makefile
 include $(LIBCOM)/bucketLib/Makefile
 include $(LIBCOM)/calc/Makefile

src/env/RULES

@@ -2,14 +2,13 @@
 # Copyright (c) 2010 UChicago Argonne LLC, as Operator of Argonne
 #     National Laboratory.
 # EPICS BASE is distributed subject to a Software License Agreement found
-# in file LICENSE that is included with this distribution. 
+# in file LICENSE that is included with this distribution.
 #*************************************************************************
 
 # This is a Makefile fragment, see src/libCom/Makefile.
 
 envData.c: $(LIBCOM)/env/envDefs.h $(LIBCOM)/env/bldEnvData.pl \
-	$(COMMON_DIR)/libcomModuleDirs.pm \
-	$(CONFIG)/CONFIG_ENV $(CONFIG)/CONFIG_SITE_ENV \
-	$(wildcard $(CONFIG)/os/CONFIG_SITE_ENV.$(T_A))
+    libcomModuleDirs.pm $(CONFIG)/CONFIG_ENV $(CONFIG)/CONFIG_SITE_ENV \
+    $(wildcard $(CONFIG)/os/CONFIG_SITE_ENV.$(T_A))
 	$(PERL) $(LIBCOM)/env/bldEnvData.pl $(QUIET_FLAG) -t $(T_A) \
 		-c $(CMPLR_CLASS) -s $(OS_CLASS) $(CONFIG)

src/env/bldEnvData.pl

@@ -1,5 +1,4 @@
 #!/usr/bin/env perl
-
 #*************************************************************************
 # Copyright (c) 2012 UChicago Argonne LLC, as Operator of Argonne
 #     National Laboratory.
@@ -14,9 +13,9 @@
 
 use strict;
 
-# This program is never installed, so it can't use FindBin to get
-# the path to the lib/perl directory.
-use lib '../O.Common';
+# This program is never installed. It uses lib '.' for the path to
+# libcomModuleDirs.pm which then sets the path to the EPICS modules.
+use lib '.';
 use libcomModuleDirs;
 
 use Getopt::Std;