There are a collection of scripts in the build repo, mostly in build/scripts/slave/chromium/ that take an option --build-dir which is ignored.
Originally, before November 2013, the value passed in as --build-dir was used and passed to build_directory.ConvertBuildDirToLegacy.
Then, iannucci@ made a CL to change rename ConvertBuildDirToLegacy (which didn't use the input build_dir anyway) to GetBuildOutputDirectory, and that CL also removed the unused parameters.
That change didn't stick and appeared to cause failures, but later pfeldman relanded most of it.
See: https://cs.chromium.org/search/?q="build-dir"
Since those --build-dir parameters have been unused for a few years, I'm pretty sure they could be removed.
Although, in http://crrev.com/2420543002, dpranke@ notes that GetBuildOutputDirectory makes some assumptions: it assumes that the build dir is src/out (or in some cases, it may be src/xcodebuild or src/build or src/out_<cros-board>.
If these assumptions seem safe, then the easiest thing to do is to remove all the ignored --build-dir parameters; otherwise, we could change things to have the passed in values of --build-dir actually used.
Comment 1 by dpranke@chromium.org
, Oct 13 2016