CVS commit: pkgsrc/mk/misc

["Roland Illig" <rillig%netbsd.org@localhost>]

Module Name:    pkgsrc
Committed By:   rillig
Date:           Mon Dec 14 00:14:48 UTC 2020

Modified Files:
        pkgsrc/mk/misc: show.mk

Log Message:
show-all: explain how to show the values of tricky variables

In most cases, the output of "bmake show-all" is reliable, but in a few
edge cases there may still be surprises.


To generate a diff of this commit:
cvs rdiff -u -r1.26 -r1.27 pkgsrc/mk/misc/show.mk

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: pkgsrc/mk/misc/show.mk
diff -u pkgsrc/mk/misc/show.mk:1.26 pkgsrc/mk/misc/show.mk:1.27
--- pkgsrc/mk/misc/show.mk:1.26 Sat Sep 12 21:27:15 2020
+++ pkgsrc/mk/misc/show.mk      Mon Dec 14 00:14:48 2020
@@ -1,4 +1,4 @@
-# $NetBSD: show.mk,v 1.26 2020/09/12 21:27:15 rillig Exp $
+# $NetBSD: show.mk,v 1.27 2020/12/14 00:14:48 rillig Exp $
 #
 # This file contains some targets that print information gathered from
 # variables. They do not modify any variables.
@@ -92,12 +92,25 @@ show-build-defs: .PHONY
 #      For each of these groups, a specialized target show-all-${group}
 #      is defined, e.g. "show-all-extract" for the "extract" group.
 #
-#      CAVEAT: Some few variable values that are shown here may be
-#      misleading. For example, make(1)'s := operator leaves references
-#      to undefined variables as-is, so they may be resolved later. So
-#      if you want to take a snapshot of the exact value of a variable,
-#      you have to use "snapshot!=printf %s ''${var:q}" instead of
-#      "snapshot:=${var}".
+#      CAVEAT: There are a few extreme edge cases in which the variable
+#      values that are shown here are not 100% correct. The closest you
+#      can get are the following:
+#
+#              * To see the unexpanded definition of a variable while the
+#                Makefile or an included file is parsed, run "bmake -dcpv",
+#                which adds a lot of debug logging.
+#              * To see the unexpanded definition of a variable at the end
+#                of parsing the Makefile, run "bmake -V VARNAME".
+#              * To see the expanded value of a variable while the Makefile
+#                or an included file is parsed, add a line of the form
+#                ".info ${VARNAME}" to that makefile.
+#              * To see the expanded value of a variable at the end of
+#                parsing the Makefile, run "bmake -v VARNAME".
+#
+#      In some cases, the actual value of a variable depends on the targets
+#      that are given on the command line, or whether bmake is run
+#      recursively, or whether a directory inside WRKSRC already exists.
+#      There is nothing the pkgsrc infrastructure can do about this.
 #
 # Keywords: debug show _vargroups
 #