depends_lib-delete short-circuits dependency list

[jmpalacios (Juan Manuel Palacios)]

A Portfile dependency rework like the following:

depends_lib-delete <port1>
depends_lib-append <port2>

Will cause MacPorts 1.4.x to error out with the following report:

Error: Error executing devel: can't set "depends_lib": invalid depspec: 
Error: Status 1 encountered during processing.

That example is taken from the autex devel variant, reported in #11796. Other ports are also affected by the same error, #11819 as an example. A known workaround is to invert the dependency rework:

depends_lib-append <port2>
depends_lib-delete <port1>

Which hints toward a limitation in our base sources: we can't write to the dependency list once we "clamp" it at the end. Any takers?

-jmpp

[kballard (Lily Ballard)]

Fixed in r24678

[jmpalacios (Juan Manuel Palacios)]

Merged into the release_1_4 branch in r24908.

-jmpp