[build] git_describe is enough, no need for a separate version specif…

…ication.

Also made some error messages nicer

Configure.pl

@@ -7,7 +7,7 @@
 use Getopt::Long;
 use Cwd;
 use lib "build/lib";
-use Parrot::CompareRevisions qw(compare_revs parse_revision_file read_config);
+use Parrot::CompareRevisions qw(compare_revs parse_revision_file read_config version_from_git_describe);
 
 MAIN: {
     my %options;
@@ -53,23 +53,24 @@
     my %config = read_config(@parrot_config_exe);
 
     # Determine the revision of Parrot we require
-    my ($req, $reqpar) = parse_revision_file;
+    my $git_describe = parse_revision_file;
+    my $parrot_version = version_from_git_describe($git_describe);
 
     my $parrot_errors = '';
-    if (!%config) { 
+    if (!%config) {
         $parrot_errors .= "Unable to locate parrot_config\n"; 
     }
     else {
         if ($config{git_describe}) {
             # a parrot built from git
-            if (compare_revs($req, $config{'git_describe'}) > 0) {
-                $parrot_errors .= "Parrot revision $req required (currently $config{'git_describe'})\n";
+            if (compare_revs($git_describe, $config{'git_describe'}) > 0) {
+                $parrot_errors .= "Parrot revision $git_describe required (currently $config{'git_describe'})\n";
             }
         }
         else {
             # not built from a git repo - let's assume it's a release
-            if (version_int($reqpar) > version_int($config{'VERSION'})) {
-                $parrot_errors .= "Parrot version $reqpar required (currently $config{VERSION})\n";
+            if (version_int($parrot_version) > version_int($config{'VERSION'})) {
+                $parrot_errors .= "Parrot version $parrot_version required (currently $config{VERSION})\n";
             }
         }
     }
@@ -78,7 +79,7 @@
         die <<"END";
 ===SORRY!===
 $parrot_errors
-To automatically clone (git) and build a copy of parrot $req,
+To automatically clone (git) and build a copy of parrot $git_describe,
 try re-running Configure.pl with the '--gen-parrot' option.
 Or, use the '--parrot-config' option to explicitly specify
 the location of parrot_config to be used to build Rakudo Perl.

build/gen_parrot.pl

@@ -28,7 +28,7 @@ =head2 DESCRIPTION
 my $slash = $^O eq 'MSWin32' ? '\\' : '/';
 
 # Determine the revision of Parrot we require
-my ($req, $reqpar) = parse_revision_file;
+my $req = parse_revision_file;
 
 {
     no warnings;
@@ -39,7 +39,7 @@ =head2 DESCRIPTION
             close $REV;
             $revision =~ s/\s.*//s;
             if (compare_revs($revision, $req) >= 0) {
-                print "Parrot $revision already available ($req required)\n";
+                print "Parrot $revision already available ($req required). that's new enough.\n";
                 exit(0);
             }
         }

build/lib/Parrot/CompareRevisions.pm

@@ -3,16 +3,29 @@ use strict;
 use warnings;
 
 use base qw(Exporter);
-our @EXPORT_OK = qw(compare_revs parse_git_describe parse_revision_file read_config);
+our @EXPORT_OK = qw(
+    parse_revision_file
+    parse_git_describe
+    version_from_git_describe
+    compare_revs
+    read_config
+);
+
+sub config_check {
+
+}
 
 sub parse_revision_file {
     my $filename = shift || 'build/PARROT_REVISION';
     open my $REQ, '<', $filename
       or die "cannot open '$filename' for reading: $!\n";
-    my ($req, $reqpar) = split(' ', <$REQ>);
+    local $/;
+    my $str  = <$REQ>;
     close $REQ;
+    $str =~ s/\A\s+//;
+    $str =~ s/\s*\z//;
 
-    return $req, $reqpar
+    return $str;
 }
 
 sub parse_git_describe {
@@ -25,6 +38,11 @@ sub parse_git_describe {
     return @c;
 }
 
+sub version_from_git_describe {
+    my @chunks = (parse_git_describe @_)[0..2];
+    return join '.', @chunks;
+}
+
 sub compare_revs {
     my ($aa, $bb) = @_;
     return  1 if $bb =~ /^r?\d+$/;

docs/release_guide.pod

@@ -107,16 +107,18 @@ the release announcement).
 =item 2.
 
 Once Parrot issues its monthly release, edit Rakudo's
-build/PARROT_REVISION file to contain the C<git describe --tags> output
-and release number corresponding to Parrot's monthly
-release.  For example, for November 2010 PARROT_REVISION file
-contained "RELEASE_2_10_1 2.10.0".  As always, test to make sure Rakudo
-still builds and passes its tests.  Once build/PARROT_REVISION
+F<build/PARROT_REVISION> file to contain the C<git describe --tags>
+output corresponding to Parrot's monthly release.
+Once C<build/PARROT_REVISION>
 has been set to the Parrot release, it must not be changed until
 after the Rakudo release.  In other words, we want each
 monthly release of Rakudo to be able to be built using
 the immediately prior release of Parrot.
 
+(Old releases required you to add both the version and the
+C<git describe> output to the PARROT_REVISION file. This is
+not necessary anymore).
+
 =item 3.
 
 The short period following the Parrot release until the