gn clean out/Default

ninja -C out/Default -j 1000 -l 20 views_mus_unittests && out/Default/views_mus_unittests --gtest_filter="*GetName*"

ninja: Entering directory `out/Default'
[1/1] Regenerating ninja files
[6677/6677] LINK ./views_mus_unittests
IMPORTANT DEBUGGING NOTE: batches of tests are run inside their
own process. For debugging a test inside a debugger, use the
--gtest_filter=<your_test_name> flag along with
--single-process-tests.
Using sharding settings from environment. This is shard 0/1
Using 1 parallel jobs.
[2205:2205:0420/122922:180634835515:ERROR:memory_mapped_file.cc(40)] Couldn't open /w/chrome/src/out/Default/ui_test.pak
[2205:2205:0420/122922:180634835583:ERROR:data_pack.cc(80)] Failed to mmap datapack
[2205:2205:0420/122922:180634835776:ERROR:memory_mapped_file.cc(40)] Couldn't open /w/chrome/src/out/Default/ui_test.pak
[2205:2205:0420/122922:180634835807:ERROR:data_pack.cc(80)] Failed to mmap datapack
/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/bits/unique_ptr.h:228: pointer std::unique_ptr<base::MemoryMappedFile, std::default_delete<base::MemoryMappedFile> >::operator->() const [_Tp = base::MemoryMappedFile, _Dp = std::default_delete<base::MemoryMappedFile>]: Assertion 'get() != pointer()' failed.
Received signal 6
#0 0x7f7527ce2f6e base::debug::StackTrace::StackTrace()
#1 0x7f7527ce2aaf base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7f752311b340 <unknown>
#3 0x7f7522d7bcc9 gsignal
#4 0x7f7522d7f0d8 abort
#5 0x7f7524ee217f std::__replacement_assert()
#6 0x7f7524ee1716 std::unique_ptr<>::operator->()
#7 0x7f7524ee04cc ui::DataPack::GetStringPiece()
#8 0x7f7526b274cb ui::ResourceBundle::GetLocalizedString()
#9 0x7f7526b257f1 ui::ResourceBundle::InitDefaultFontList()
#10 0x7f7526b25a18 ui::ResourceBundle::InitSharedInstanceWithPakPath()
#11 0x00000047689f views::ViewTestSuite::Initialize()
#12 0x0000004ee8ca base::TestSuite::Run()

I see this comment in ui/views/mus/BUILD.gn

  # TODO(thakis): This should be a data_deps on //ui/resources:ui_test_pak, but
  # that has no effect.  (See similar TODOs elsewhere ui_test.pak is listed)