Various fixes for Kconfiglib:

- remove the old setting of LANG in BLFS/Makefile
- explicitly use python3, because now menuconfig.py has #!/usr/bin/python,
  we may have only python3 available
- add quotes in Config.in for BLFS

BLFS/Makefile

@@ -11,10 +11,6 @@ else
   Q = @
 endif
 
-# Known behavior
-LANG=C
-LC_ALL=C
-
 # Makefile should reside in a directory where there are two subdirectories
 # initially:
 TOPDIR           = $(shell pwd)
@@ -102,7 +98,7 @@ $(BOOK_XML): $(CONFIG_OUT)
 
 $(CONFIG_OUT): $(CONFIG_CONFIG_IN)
 	$(Q)CONFIG_="" KCONFIG_CONFIG=configuration \
-	    $(MENU)/menuconfig.py $(CONFIG_CONFIG_IN)
+	    python3 $(MENU)/menuconfig.py $(CONFIG_CONFIG_IN)
 
 $(CONFIG_CONFIG_IN): $(PACK_LIST) $(XSLDIR)/gen_config.xsl
 	$(Q)xsltproc --nonet -o $@ $(XSLDIR)/gen_config.xsl $(PACK_LIST)

BLFS/xsl/gen_config.xsl

@@ -25,9 +25,9 @@ choice
 endchoice
 config  MAIL_SERVER
         string
-        default sendmail        if MS_sendmail
-        default postfix         if MS_postfix
-        default exim            if MS_exim
+        default "sendmail"        if MS_sendmail
+        default "postfix"         if MS_postfix
+        default "exim"            if MS_exim
 
 endmenu
 

Makefile

@@ -13,7 +13,8 @@ all: menuconfig
 
 menuconfig:
 	@cp -a configuration configuration.old 2>/dev/null || true
-	@CONFIG_="" KCONFIG_CONFIG=configuration $(CONFIG)/menuconfig.py $(CONFIG_CONFIG_IN)
+	@CONFIG_="" KCONFIG_CONFIG=configuration \
+	    python3 $(CONFIG)/menuconfig.py $(CONFIG_CONFIG_IN)
 
 # Clean up