Mark,
To answer your questions as best I can.
1) Is it possible to merge the new main/pom.xml into top-level POM?
Creating a new directory just to separate the main ABCL build
instructions seems a little wrong to me.
This was done because there's no need for the abcl artifact to include the contents of the
abcl-contrib artifact, or vice-versa. It may be possible but it isn't something I know how to do. Typically the sources for abcl would be included in the main/ (abcl) module directory, so the wrongness is that the file structure of ABCL was not designed for maven.
2) Why not use the Ant instructions for building the actual abcl.jar
artifact? It would be better for future maintenance not to have two
sets of instructions for constructing deployment artifacts.
If ant builds the jar I don't believe maven will pick it up. The abcl-contrib that is deployed by maven isn't the one that is built by ant, and is ignored. It is the one built by maven that's deployed. The ant compiling process is dumping all of the compiled lisp files where maven knows to find them for building the jar, and that is how it works. I don't believe maven will pick up a jar generated by a third party process when using the install or deploy targets.
3) Can we make the GPG signing optional for the 'install' target?
Maven does provide the ability to create profiles so yes, a profile could be created which contains the GPG signing so that only builds with that profile would include the GPG signing.