Detecting inconsistent revisions of shared sources in SVN

I have an SVN repository containing several components:

• LibraryA
• LibraryB - depends on LibraryA
• Application - depends on LibraryB and LibraryA

More detailed structure (branches and tags are not related to the problem):

• LibraryA
  • LibraryA_code
• LibraryB
  • LibraryB_code
  • svn:externals to a fixed revision R1 of LibraryA_code
• Application
  • Application_code
  • svn:externals to a fixed revision R2 of LibraryA_code
  • svn:externals to a fixed revision R3 of LibraryB_code

The problem I'm trying to solve is automatic detection of situation when R2 differs from R1 (breaking expectations of LibraryB_code) and notification about this (e.g. build failure).

I'll describe in an answer the only solution which I see for now, but I hope for something more elegant :)

Environment: Windows, Vi开发者_如何学Csual Studio, SVN.

When you modify the svn:externals property of Library B and commit this change, you create a new revision of Library B. This means, the Application repository is still consistent. You only need to worry when you modify an svn:externals property of Application itself.

This case can be dealt with in a repository hook for the Application repository. That hook checks out the specified revision of Library B to a temporary directory and compares its required version of Library A with that of the version required by the application. See Repository Hooks for a list of available hooks.

Store for each library a file with required revision for each dependency. Add a post-build event which compares these revisions with results of "svnversion" and breaks build if any check fails.

Drawbacks:

1. requires installed command-line svn client (while developer may be happy with TortoiseSVN alone
2. doesn't work for exported sources, only for checked out working copies