我想使用TDD方法来开发repository_rule，该方法可以处理python sdks的下载
当我描述创建自定义测试工作区的简单测试用例时，我注意到py_test内部的RunBazel指令执行缓慢-每次执行大约需要2分钟，实际上，这不允许我使用它
有一个描述问题的提交-e7d33f7
./bazel-out/k8-fastbuild/bin/src/bazel test //src/test/py/bazel:nested_py_test --test_verbose_timeout_warnings --spawn_strategy=standalone --show_timestamps
（我尝试使用不同的标志）导致输出为
(17:04:24) INFO: Elapsed time: 119.657s, Critical Path: 119.52s
(17:04:24) INFO: 2 processes: 2 local.
(17:04:24) INFO: Build completed, 1 test FAILED, 2 total actions
//src/test/py/bazel:nested_py_test FAILED in 119.4s
我尝试了bazel的主版本（74bf7888b7），并发布了一个（0.24.1）
用py_binary进行测试需要花费 6s 来执行，花费py_test-大约需要 114s
py_test调用的标准输出是
Starting local Bazel server and connecting to it...
(00:17:10) INFO: Current date is 2019-04-29
(00:17:10) Loading:
(00:17:10) Loading: 0 packages loaded
(00:17:11) Analyzing: target @nested_py_workspace//:test (1 packages loaded, 0 targets configured)
(00:17:12) Analyzing: target @nested_py_workspace//:test (16 packages loaded, 78 targets configured)
(00:17:13) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:14) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:15) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:16) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:17) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:18) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:19) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:21) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:22) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:24) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:27) Analyzing: target @nested_py_workspace//:test (17 packages loaded, 148 targets configured)
(00:17:29) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:32) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:36) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:39) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:44) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:49) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:17:55) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:18:02) Analyzing: target @nested_py_workspace//:test (18 packages loaded, 149 targets configured)
(00:18:10) Analyzing: target @nested_py_workspace//:test (19 packages loaded, 185 targets configured)
(00:18:19) Analyzing: target @nested_py_workspace//:test (19 packages loaded, 185 targets configured)
(00:18:29) Analyzing: target @nested_py_workspace//:test (19 packages loaded, 185 targets configured)
(00:18:42) Analyzing: target @nested_py_workspace//:test (19 packages loaded, 185 targets configured)
(00:18:55) Analyzing: target @nested_py_workspace//:test (19 packages loaded, 185 targets configured)
(00:19:02) INFO: Analyzed target @nested_py_workspace//:test (20 packages loaded, 302 targets configured).
(00:19:02) INFO: Found 1 target...
(00:19:02) [0 / 3] [Prepa] Creating source manifest for @nested_py_workspace//:test
和by_binary
Starting local Bazel server and connecting to it...
(00:22:07) INFO: Current date is 2019-04-29
(00:22:07) Loading:
(00:22:07) Loading: 0 packages loaded
(00:22:08) Analyzing: target @nested_py_workspace//:test (1 packages loaded, 0 targets configured)
(00:22:09) Analyzing: target @nested_py_workspace//:test (12 packages loaded, 69 targets configured)
(00:22:09) INFO: Analyzed target @nested_py_workspace//:test (15 packages loaded, 129 targets configured).
(00:22:09) INFO: Found 1 target...
py_test分析的个人资料
=== PHASE SUMMARY INFORMATION ===
Total launch phase time 1.082 s 0.85%
Total init phase time 306 ms 0.24%
Total loading phase time 476 ms 0.38%
Total analysis phase time 124.640 s 98.44%
Total preparation phase time 14.6 ms 0.01%
Total execution phase time 70.6 ms 0.06%
Total finish phase time 28.2 ms 0.02%
Total run time 126.618 s 100.00%
...
=== ANALYSIS PHASE INFORMATION ===
Total analysis phase time 124.640 s
Total time (across all threads) spent on:
Type Total Count Average
INFO 0.05% 69 3.77 ms
CREATE_PACKAGE 0.02% 26 3.95 ms
VFS_STAT 0.00% 607 0.01 ms
VFS_DIR 0.00% 14 0.07 ms
VFS_READLINK 0.00% 209 0.03 ms
VFS_MD5 0.21% 43 25.6 ms
VFS_DELETE 0.01% 14 1.92 ms
VFS_OPEN 0.00% 574 0.02 ms
VFS_READ 0.01% 30058 0.00 ms
VFS_WRITE 0.25% 557440 0.00 ms
VFS_GLOB 0.00% 41 0.43 ms
SKYFRAME_EVAL 23.54% 4 31.093 s
SKYFUNCTION 38.36% 2034 99.7 ms
STARLARK_PARSER 0.01% 60 1.28 ms
STARLARK_USER_FN 37.48% 1075 184 ms
STARLARK_BUILTIN_FN 0.06% 1720 0.17 ms
...
所以我想知道：
py_test指令