bitbake: runqueue.py: check whether multiple versions of the same PN are due to be built

There would be an race issue if we:

$ bitbake make-3.81 make-3.82

This because they are being built at the same time which would cause
unexpected problems, for example:

[snip]
ERROR: Package already staged (/path/to/tmp/sstate-control/manifest-qemux86-make.populate-sysroot)?!
ERROR: Function failed: sstate_task_postfunc
[snip]

Or there would be python's strack trace such as:

[snip]
 *** 0004:    mfile = open(manifest)
     0005:    entries = mfile.readlines()
     0006:    mfile.close()
     0007:
     0008:    for entry in entries:
Exception: IOError: [Errno 2] No such file or directory: xxx
[snip]

[YOCTO #5094]

We can quit earlier to avoid this kind of issue when two versions of the same PN
are going to be built since this isn't supported.

(Bitbake rev: ab377c00c33a2d296bfda1b0b6c2a62b29d1004f)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/runqueue.py

@@ -696,6 +696,14 @@ class RunQueueData:
                     prov_list[prov].append(fn)
         for prov in prov_list:
             if len(prov_list[prov]) > 1 and prov not in self.multi_provider_whitelist:
+                seen_pn = []
+                # If two versions of the same PN are being built its fatal, we don't support it.
+                for fn in prov_list[prov]:
+                    pn = self.dataCache.pkg_fn[fn]
+                    if pn not in seen_pn:
+                        seen_pn.append(pn)
+                    else:
+                        bb.fatal("Multiple versions of %s are due to be built (%s). Only one version of a given PN should be built in any given build. You likely need to set PREFERRED_VERSION_%s to select the correct version or don't depend on multiple versions." % (pn, " ".join(prov_list[prov]), pn))
                 msg = "Multiple .bb files are due to be built which each provide %s (%s)." % (prov, " ".join(prov_list[prov]))
                 if self.warn_multi_bb:
                     logger.warn(msg)
@@ -703,7 +711,6 @@ class RunQueueData:
                     msg += "\n This usually means one provides something the other doesn't and should."
                     logger.error(msg)
 
-
         # Create a whitelist usable by the stamp checks
         stampfnwhitelist = []
         for entry in self.stampwhitelist.split():