[MNG-6752] submodule with $revision version can't be referenced by a normal version number

**[Martin K](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=martin.koegler@brz.gv.at)** opened **[MNG-6752](https://issues.apache.org/jira/browse/MNG-6752?redirect=false)** and commented

In the following example, pp/pom.xml can't reference its parent with a specific version number ("\1-SNAPSHOT\") - Unless pp1:pp-pom:pom:1-SNAPSHOT is already present in a maven repository, the build will fail.

Maven reads the parent poms and caches them, before resolving $revision. Therefore it just caches the artifact version "${revsion}" and fails to load the local parent pom, if the parent reference does not also use the version "${revision}"

Precondition: Non of these artificats is already present in a local or remote maven repository.

File pom.xml:

```

4.0.0

pp
y-pom
yy
pom
1-SNAPSHOT

pp1
pp

1-SNAPSHOT

```

File ./pp/pom.xml:

```

4.0.0

pp
pp-pom
PP
pom
${revision}

pp1
pp-pom
1-SNAPSHOT

../pp1/pom.xml


1-SNAPSHOT

```

File ./pp1/pom.xml:

```

4.0.0

pp1
pp-pom
PP
pom
${revision}

1-SNAPSHOT

```

 

---

**Affects:** 3.6.1

Reproduce the failure using the root pom.xml, pp/pom.xml, and pp1/pom.xml shown in the issue, with the artifacts absent from local and remote repositories. Start by tracing how Maven reads and caches parent POMs before resolving ${revision}. Done means the build succeeds when pp/pom.xml references its parent with the concrete 1-SNAPSHOT version.

Written by the indexing model from the issue text.