Are subversion externals an antipattern?

Question

Subversion lets you embed working copies of other repositories using externals, allowing easy version control of third-party library software in your project.

While

Answer 1

There are definite flaws in subversion externals, but we seem to use them reasonably successfully for including libraries (both our own and vendor) that the current project depends on. So I don't see them as an "anti-pattern". The important usage points for me are:

• They point to a specific revision or tag (never the head) of the other project.
• They are inserted into the current project well away from its own source code etc (e.g. in a subdirectory called "support files").
• They refer only to the other projects "interface" files (e.g. include folder) and binary libraries (i.e. we don't get the full source of the other project).

I too would be interested in any major risks of this arrangement, and better approaches.