Add private-B-change-removes-B-to-A-dep

[rsalvador]

Makes a private change in B that removes the dependency of B on A, this causes and change in the jdeps of B and thus a java compiler classpath change when recompiling C, thus C is recompiled:

$ ./script.sh private-B-change-removes-B-to-A-dep
...
INFO: Elapsed time: 0.709s, Critical Path: 0.21s
INFO: 4 processes: 1 internal, 1 darwin-sandbox, 2 worker.
INFO: Build completed successfully, 4 total actions
...
$ cat patches/private-B-change-removes-B-to-A-dep.explain.log
Executing action 'BazelWorkspaceStatusAction stable-status.txt': unconditional execution is requested.
Executing action 'Building libB.jar (1 source file)': One of the files has changed.
Executing action 'Extracting interface for jar bazel-out/darwin_x86_64-fastbuild/bin/libB.jar': One of the files has changed.
Executing action 'Building libC.jar (1 source file)': One of the files has changed.

Those are the rebuilds for this scenario:

• default: recompiles B
• classpath=bazel: recompiles B/C (C recompiled because compile classpath changed)
• classpath=bazel + empty jdeps (direct deps only): recompiles B

[guw]

@rsalvador You need to provide the output of the bazel binary.

I confirmed in fmeum#1 that the message in the explain.log is misleading. In your case, Building libC.jar (1 source file) will not be a rebuild but a disk cache hit.

[rsalvador]

I confirmed in fmeum#1 that the message in the explain.log is misleading. In your case, Building libC.jar (1 source file) will not be a rebuild but a disk cache hit.

there is no cache hit because the java compiler classpath changed (libA.jar is no longer in the classpath when compiling C)