[jira] [Commented] (MNG-5899) Reactor is no longer using the dependency reduced pom created by maven-shade-plugin

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MNG-5899?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15269077#comment-15269077 ] 

ASF GitHub Bot commented on MNG-5899:
-------------------------------------

Github user aqueance commented on the pull request:

    https://github.com/apache/maven/pull/69#issuecomment-216595519
  
    In addition to the problems mentioned above, that [hack](https://github.com/apache/maven/blame/3533599e42a4a563abca33a69ed0f34c19815479/maven-aether-provider/src/main/java/org/apache/maven/repository/internal/DefaultArtifactDescriptorReader.java#L287) also breaks the transitive dependency collection functionality in general, because it employs a [Reactor-wide](https://github.com/apache/maven/blame/3533599e42a4a563abca33a69ed0f34c19815479/maven-core/src/main/java/org/apache/maven/ReactorReader.java#L69) [cache](https://github.com/apache/maven/blame/3533599e42a4a563abca33a69ed0f34c19815479/maven-core/src/main/java/org/apache/maven/ReactorReader.java#L145) of parsed POMs that fails to take into account the `RepositorySystemSession` contexts in which the cached POMs were parsed.
    
    A cache with a broken key scheme is not a cache, it's a source of unexpected behavior: if any `RepositorySystemSession` is at play other than the one used by the Reactor, collecting transitive dependencies now results in a dependency tree that is **practically random**, as it depends on:
    
      * what POMs have already been parsed by the Reactor during the build (this is why splitting the build into multiple phases works around the problems caused by this bug),
      * what other `RepositorySystemSession` instances have been used to parse and cache POMs so far,
      * what command line arguments were used to invoke Maven.
    
    I have a Maven plugin that computes transitive dependencies of the host project by cloning the `RepositorySystemSession` used by the reactor to set properties that activate build profiles, which in turn contain dependencies to be taken into account when computing a custom dependency tree.
    
    The API to do so is [public](http://wiki.eclipse.org/Aether) so one expects the functionality work, which it did until Maven 3.3 came along. Now because of that bug, the functionality stopped working reliably.
    
    Speed is important, sure, but correct functionality is probably even more so. So please remove that hack, and if its function is indeed necessary, then it needs to be replaced with a proper cache, one that takes the active `RepositorySystemSession` into account.


> Reactor is no longer using the dependency reduced pom created by maven-shade-plugin
> -----------------------------------------------------------------------------------
>
>                 Key: MNG-5899
>                 URL: https://issues.apache.org/jira/browse/MNG-5899
>             Project: Maven
>          Issue Type: Bug
>    Affects Versions: 3.3.1, 3.3.3
>            Reporter: Trask Stalnaker
>
> This works with maven 3.2.5 and prior, but does not work with the latest releases (3.3.1 and 3.3.3), or master (tested against 3.3.7-SNAPSHOT).
> I did some bisecting and found the commit that caused the breakage:
> https://github.com/apache/maven/commit/be3fb200326208ca4b8c41ebf16d5ae6b8049792
> In particular, this commit introduced some code to not rebuild the model if it was already loaded during reactor resolution.
> This is causing maven not to use the dependency reduced pom created by the maven-shade-plugin.
> Removing this code fixes the situation.  I'm hoping that code was just introduced as a performance optimization, and that I haven't broken anything functionally by removing it (the tests still pass at least).
> I will submit a pull request with the change for review.
> Here is the original maven-shade-plugin issue as reported by the Apache Storm team: https://issues.apache.org/jira/browse/MSHADE-206



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