Maven RubyGems improvements

It needs to be less verbose (but provide debugging information on demand).

$ jruby -S irb
irb(main):001:0> require 'rubygems'
Installing from Maven using install at /Users/asari/Development/src/apache-maven-3.0/bin
=> true
irb(main):002:0> 

It needs to provide a better error message if $M2_HOME is invalid.

$ jruby -S gem install org.clojure.clojure --no-ri --no-rdoc
/usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems.rb:883:in `source_index': uninitialized constant Gem::SourceIndex (NameError)
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems.rb:213:in `activate'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems.rb:1082:in `gem'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/maven_gemify.rb:78:in `init'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/maven_gemify.rb:201
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/maven_gemify.rb:10:in `require'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/specification.rb:10
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/specification.rb:8:in `require'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:8
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:1105:in `require'
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems.rb:1105
	from /usr/local/jruby/lib/ruby/site_ruby/1.8/rubygems.rb:8:in `require'
	from /usr/local/jruby/bin/gem:8

I fixed the excessive logging of "Installing from Maven" so that it only fires during init of maven_gemify, which fires only once when maven stuff is needed during install.

Confirmed on the bad M2_HOME result; definitely not helpful

does it make sense to leave out M2_HOME since it is really enough to have mvn (version 3) on the executable path ? to run maven you do not need to set M2_HOME.

please pull the fix for detecting "wrong M2_HOME" and some little cleanups from https://github.com/mkristian/jruby

since the gemify code is also used by the nexus-gem-plugin I think we leave the code location as is. I am happy to give commit permissions to someone (or more) to the jruby-maven-plugins repo. then we need to add this person to allow releases via oss.sonatype.org

FYI torquebox has also access rights for the git-repo as well for oss.sonatype.org releases. this altogether should give enough "certainty".

Re: no M2_HOME, just use executable

I agree...if it's possible to determine the location just from PATH, we should do it. But if M2_HOME is a standard env var for maven, and the user has set it, that should take priority.

In order of priority:

1. M2_HOME if set
2. Maven from path if found (and I assume there's still work needed to support Maven 2?)
3. raise, request ruby-maven gem be installed

If ruby-maven is installed, should that fit higher into priority?

Re: gemify code location/ownership

I'm comfortable with that. Getting commit rights for at least one of us would be helpful, in case we need to make a fix at a time when you are unable to add us. I suppose I'd nominate me, since I've poked around maven code and your plugins more than others on JRuby team. Ok?

Your changes (improving handling of wrong M2_HOME and other cleanup) have been pushed to master.

commit c5a40fbeec14e5589446861012d117d6198376a8
Author: mkristian <m.kristian@web.de>
Date: Thu Nov 4 18:27:57 2010 +0530

cleaned up a little and detect wrong M2_HOME

Signed-off-by: Charles Oliver Nutter <headius@headius.com>

@headius you are not on https://github.com/mkristian/jruby-maven-plugin now. concerning oss.sonatype.org I would need you to sign-up on https://issues.sonatype.org and let me know your username so I can ask oss.sonatype.org to give you permission to release new versions (see also https://docs.sonatype.org/display/Repository/Sonatype+OSS+Maven+Repository+Usage+Guide).

hoops: @headius you ARE on github now !!!!

I have created an account on issues.sonatype as username "headius". Thank you for giving me access!

Kristian: Where do we stand on supporting maven 2? Ideally this stuff would work for anyone that has a M2 install right now. I know you said it might be close, but I don't think you ever said it was working, correct?

Headius: maven2 support - hmm. the gap between maven2 and maven3 became bigger between maven-3.0-beta-2 and maven-3.0-beta-3 since they changed the api which is used by geminfy. in meanwhile I started to add ruby support for polyglot-maven-jruby as well for mvnsh and both are maven3 based. so in the end I removed all the maven2 api until now. though the functionality is there in maven2 but supporting two APIs for gemify and two APIs for embedding maven sounds a bit much. in the end distance to use it is just about 2MB download of ruby-maven which works nicely side by side with any maven installation (version 1 or 2 or 3). sorry if I made a promise which I can not keep - at least not right now.

referring to following issue

http://maven-users.828.n2.nabble.com/problems-with-javax-transaction-jta-on-maven-central-td5761597.html

I found that there some artifacts have no jar on maven central due to licensing issues. like http://repo2.maven.org/maven2/javax/transaction/jta/1.0.1B/ which has only the pom which carries the download url. an other example are the orcale jdbc drivers.

these cases should produce some descriptive error messages

Just checking on on this one. We have a few items outstanding I'll list below.

• Maven 2 support: ok...I guess this one isn't really possible, since the APIs have diverged so much. We should detect attempts to run against Maven 2 and produce a useful message recommending the ruby-maven gem (or recommending the user update Maven.
• Gem names should use :, since it turns out that . is a valid character in gem names (and the Cool.io package uses it).
• Bad poms or artifacts like the javax.transaction.jta artifact mentioned should produce reasonable errors; some of them currently just belch out a giant Java error trace.
• ruby-maven needs a full release, so people can install it without -pre
• Nick was looking into maintaining a fork of RubyGems with JRuby-specific branches where we could store these changes. That should probably happen before 1.6.
• We should investigate what happens when someone does a "gem update --system", which will likely wipe out the Maven changes we've added.

We'll have an RC cycle for JRuby 1.6 during which we can test out and fix issues as they arise.

buildr also uses ':' as well so the precedent is well established.

':' is not allowed in artifactId by maven-3. but I can build a gem with such character in the name. actually the rubygems side breaks the moment the first gem with such a name gets pushed to rubygems. and people will see quite a few of such names through this maven-gemify feature. in the ned we would need something which is not allowed by rubygems but which we can force to use anyways for our gems. if that is not possible then maybe something better then just ':': on top of the ':' separator add a prefix which people do NOT LIKE to use themselves: 'maven:' )

We need to keep in mind a point of paramount importance: the names we choose must work in gemspecs. If I push a gem that depends on a name that breaks RubyGems, many people would be very unhappy with me...

The colon version appears to fail in RubyGems when attempting to install dependencies. Could just be a missing piece of logic? Below, both forms build ok but only the all-dots form manages to resolve and install the dependency:

~/projects/cloby ➔ gem build cloby.gemspec 
WARNING:  description and summary are identical
  Successfully built RubyGem
  Name: cloby
  Version: 0.0.2
  File: cloby-0.0.2-java.gem

~/projects/cloby ➔ gem uninstall org.clojure.clojure
Successfully uninstalled org.clojure.clojure-1.2.0-java

~/projects/cloby ➔ gem install cloby-0.0.2-java.gem 
ERROR:  Error installing cloby-0.0.2-java.gem:
	cloby requires org.clojure:clojure (>= 0, runtime)

~/projects/cloby ➔ vi cloby.gemspec 

~/projects/cloby ➔ gem build cloby.gemspec 
WARNING:  description and summary are identical
  Successfully built RubyGem
  Name: cloby
  Version: 0.0.2
  File: cloby-0.0.2-java.gem

~/projects/cloby ➔ gem install cloby-0.0.2-java.gem 
Successfully installed org.clojure.clojure-1.2.0-java
Successfully installed cloby-0.0.2-java
2 gems installed

I'm not opposed to adding another item to the name, like prefixing it with "mvn." and unconditionally treating that as a maven gem. That is similar to the namespacing people do by inserting their username in front of an existing gem to make it their own release of that gem (a la mojombo-jekyll and similar). I just worry about the names getting too long. Perhaps four characters is not too much to ask?

the problem with the ':' is that the gemify-maven-plugin needs to use the ':' as well when setting up the gemspec for the gem - right now it use the '.'. so the above issue can be fixed. personally I would use the 'mvn:' on top of it to be on the safe side in the long run.

+1 on 'mvn:' namespacing, for the sake of clarity and code simplicity

'mvn:' would solve this problem as well: http://jira.codehaus.org/browse/JRUBY-5344

As of 2fc90bd0 I think most of these issues are fixed. Open a new bug for new features/suggestions.