Re: [m2e-users] Run As Maven Build vs. Eclipse auto build

[Bruno Haible <bruno.haible@xxxxxxxxxx>]

Stephan Herrmann writes:
> I've observed many builds failing in situations that *might* have been
> caused by bad interaction between an explicit build triggered by
> "Run As ... > Maven build ..." and the Eclipse auto build.

Yes, this is well-known: m2e forces the use of the *same classes 
directories*
(target/classes and target/test-classes in the usual setup) for both maven 
and
Eclipse (see https://dev.eclipse.org/mhonarc/lists/m2e-users/msg05030.html
).

Weird errors can be the consequence:
- NoSuchMethodException for access$0.
- A running program (launched from Eclipse) doesn't find its resources any
  more, because an "mvn clean install" command is being run on the command
  line.

The workaround is:
You have to be careful when running maven on the command line (outside
Eclipse or through "Run As ... > Maven build ..."). You must avoid that a
maven build inside Eclipse and a maven build outside Eclipse are running 
at
the same time.
This means:
  - As long as Eclipse displays "Building workspace...", don't run a maven
    build on the command line.
  - As long as a maven build on the command line is running, don't save 
any
    modified file in Eclipse, nor pull any changes from the version 
control
    system.

Of course, I too would be interested to know a better workaround than 
that.

Bruno

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Bruno Haible                            Email: <bruno.haible@xxxxxxxxxx>
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