Issue with p2 mirror configuration

[fipro78]

I noticed an issue that the mirror configuration for a p2 repository is not working correctly. Honestly I am not sure if the issue is related to a trailing slash in the target definition or if the issue is somewhere else.

I tried to build Eclipse Equinox locally behind a corporate proxy, but I get strange errors. The error message is:

Failed to resolve target definition file:/C:/Users/xxx/.m2/repository/org/eclipse/eclipse-sdk-prereqs/4.29.0-SNAPSHOT/eclipse-sdk-prereqs-4.29.0-SNAPSHOT.target: Failed to load p2 metadata repository from location https://download.eclipse.org/tools/orbit/downloads/drops/R20201118194144/repository/: Unable to read repository at https://download.eclipse.org/tools/orbit/downloads/drops/R20201118194144/repository. ConnectException: UnresolvedAddressException

I tried to configure a local mirror in my settings.xml like this:

   <mirror>
	  <id>orbit202305-local</id>
	  <mirrorOf>https://download.eclipse.org/tools/orbit/downloads/drops/R20230531010532/repository</mirrorOf>
	  <url>file:///C:/Development/update-sites/orbit-202305/</url>
	  <layout>p2</layout>
	  <mirrorOfLayouts>p2</mirrorOfLayouts>
   </mirror>

But the mirror doesn't seem to be used. I checked the target file that is downloaded in the local maven repository, and there I see a trailing slash in the repository location. The Tycho docs say, there should be no trailing slash.

The settings.xml is at the default location.

The info message before the failure is the following:

[INFO] Loading repository '' from mirror 'orbit202305-local' at 'file:///C:/Development/update-sites/orbit-202305/'
[INFO] ### Using TychoRepositoryTransport for remote P2 access ###
[INFO]     Cache location:         C:\Users\fad8pl\.m2\repository\.cache\tycho
[INFO]     Transport mode:         online
[INFO]     Http Transport type:    Java11Client
[INFO]     Update mode:            cache first
[INFO]     Minimum cache duration: 60 minutes
[INFO]       (you can configure this with -Dtycho.p2.transport.min-cache-minutes=<desired minimum cache duration>)
[INFO] Downloading from p2: https://download.eclipse.org/tools/orbit/downloads/drops/R20201118194144/repository/p2.index

The eclipse-sdk-prereqs has trailing slashes in the location. As I said, I am not sure if this is really the issue, or if the mirror is not used. Can't tell if the mirror matching is too strict in the comparison. If this is really the case, IMHO Tycho should be less strict here and remove that requirement.