$ head -c12582912 /dev/zero > 12MB.zero
$ arc upload 12MB.zero --trace --conduit-uri=https://secure.phabricator.com/
libphutil loaded from '/Users/epriestley/dev/core/lib/libphutil/src'.
arcanist loaded from '/Users/epriestley/dev/core/lib/arcanist/src'.
Config: Reading user configuration file "/Users/epriestley/.arcrc"...
Config: Did not find system configuration at "/etc/arcconfig".
Working Copy: No candidate locations for .arcconfig from this working directory.
Working Copy: Path "/Users/epriestley/Desktop" is not in any working copy.
>>> [0] <conduit> conduit.connect() <bytes = 560>
>>> [1] <http> https://secure.phabricator.com/api/conduit.connect
<<< [1] <http> 474,819 us
<<< [0] <conduit> 475,006 us
Uploading '12MB.zero'...
>>> [2] <conduit> file.allocate() <bytes = 294>
>>> [3] <http> https://secure.phabricator.com/api/file.allocate
<<< [3] <http> 136,082 us
<<< [2] <conduit> 136,277 us
Beginning chunked upload of large file...
>>> [4] <conduit> file.querychunks() <bytes = 217>
>>> [5] <http> https://secure.phabricator.com/api/file.querychunks
<<< [5] <http> 148,677 us
<<< [4] <conduit> 148,832 us
Uploading chunks (3 chunks to upload).
>>> [6] <conduit> file.uploadchunk() <bytes = 5592721>
>>> [7] <http> https://secure.phabricator.com/api/file.uploadchunk
<<< [7] <http> 9,311,735 us
<<< [6] <conduit> 9,311,963 us
>>> [8] <conduit> file.uploadchunk() <bytes = 5592721>
>>> [9] <http> https://secure.phabricator.com/api/file.uploadchunk
<<< [9] <http> 9,834,775 us
<<< [8] <conduit> 9,834,982 us
>>> [10] <conduit> file.uploadchunk() <bytes = 5592715>
>>> [11] <http> https://secure.phabricator.com/api/file.uploadchunk
<<< [11] <http> 8,446,483 us
<<< [10] <conduit> 8,446,689 us
>>> [12] <conduit> file.info() <bytes = 213>
>>> [13] <http> https://secure.phabricator.com/api/file.info
<<< [13] <http> 132,587 us
<<< [12] <conduit> 132,737 us
  F358762 12MB.zero: https://secure.phabricator.com/F358762

Done.