Fail to fetch bazel_skylib following your #3 instruction on MacOS Catalina

[87003697]

Hi, developer! Looks like I got the same problem as #19 and #3 did when I'm gonna run Hand Tracking Demo with Webcam(CPU) following your Markdown Files. When I run this code

$ bazel build -c opt --define MEDIAPIPE_DISABLE_GPU=1 \
mediapipe/examples/desktop/multi_hand_tracking:multi_hand_tracking_cpu

It returns

ERROR: An error occurred during the fetch of repository 'bazel_skylib':
java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out

ERROR: no such package '@bazel_skylib//lib': java.io.IOException: 
Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out

ERROR: no such package '@bazel_skylib//lib': java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out

After reading your answer to #3, I modified your cmd to meet my need, which is

$ bazel build -c opt --define MEDIAPIPE_DISABLE_GPU=1 \
  --distdir=./bazel_skylib/ \
  --repository_cache=./bazel_skylib/ \
  --keep_going \
mediapipe/examples/desktop/multi_hand_tracking:multi_hand_tracking_cpu

Take note that the sub directory bazel_skylib is where I downloaded, saved and tarred ( I mean decompress) your repo bazel-skylib.0.8.0.tar.gz.
This time what printed is below

INFO: Writing tracer profile to '/private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/command.profile.gz'
INFO: Call stack for the definition of repository 'bazel_skylib' which is a http_archive (rule definition at /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_tools/tools/build_defs/repo/http.bzl:292:16):
 - /Users/zhiyuanma/Desktop/action_detection/mediapipe/WORKSPACE:6:1
WARNING: Download from https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz failed: class java.io.IOException connect timed out
ERROR: An error occurred during the fetch of repository 'bazel_skylib':
   java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out
ERROR: no such package '@bazel_skylib//lib': java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out
Internal error thrown during build. Printing stack trace: java.lang.IllegalStateException: no such package '@bazel_skylib//lib': java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out
	at com.google.common.base.Preconditions.checkState(Preconditions.java:507)
	at com.google.devtools.build.lib.skyframe.SkyframeExecutor.loadTargetPatterns(SkyframeExecutor.java:2841)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.evaluateTargetPatterns(AnalysisPhaseRunner.java:170)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.execute(AnalysisPhaseRunner.java:79)
	at com.google.devtools.build.lib.buildtool.BuildTool.buildTargets(BuildTool.java:141)
	at com.google.devtools.build.lib.buildtool.BuildTool.processRequest(BuildTool.java:268)
	at com.google.devtools.build.lib.runtime.commands.BuildCommand.exec(BuildCommand.java:99)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:540)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:204)
	at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:596)
	at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$2(GrpcServerImpl.java:647)
	at java.base/java.lang.Thread.run(Unknown Source)

INFO: Elapsed time: 57.719s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (0 packages loaded)
Internal error thrown during build. Printing stack trace: java.lang.IllegalStateException: no such package '@bazel_skylib//lib': java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out
	at com.google.common.base.Preconditions.checkState(Preconditions.java:507)
	at com.google.devtools.build.lib.skyframe.SkyframeExecutor.loadTargetPatterns(SkyframeExecutor.java:2841)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.evaluateTargetPatterns(AnalysisPhaseRunner.java:170)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.execute(AnalysisPhaseRunner.java:79)
	at com.google.devtools.build.lib.buildtool.BuildTool.buildTargets(BuildTool.java:141)
	at com.google.devtools.build.lib.buildtool.BuildTool.processRequest(BuildTool.java:268)
	at com.google.devtools.build.lib.runtime.commands.BuildCommand.exec(BuildCommand.java:99)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:540)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:204)
	at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:596)
	at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$2(GrpcServerImpl.java:647)
	at java.base/java.lang.Thread.run(Unknown Source)
java.lang.IllegalStateException: no such package '@bazel_skylib//lib': java.io.IOException: Error downloading [https://github.com/bazelbuild/bazel-skylib/releases/download/0.8.0/bazel-skylib.0.8.0.tar.gz] to /private/var/tmp/_bazel_zhiyuanma/79a8e7d79be2c406b0c21b61381c7456/external/bazel_skylib/bazel-skylib.0.8.0.tar.gz: connect timed out
	at com.google.common.base.Preconditions.checkState(Preconditions.java:507)
	at com.google.devtools.build.lib.skyframe.SkyframeExecutor.loadTargetPatterns(SkyframeExecutor.java:2841)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.evaluateTargetPatterns(AnalysisPhaseRunner.java:170)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.execute(AnalysisPhaseRunner.java:79)
	at com.google.devtools.build.lib.buildtool.BuildTool.buildTargets(BuildTool.java:141)
	at com.google.devtools.build.lib.buildtool.BuildTool.processRequest(BuildTool.java:268)
	at com.google.devtools.build.lib.runtime.commands.BuildCommand.exec(BuildCommand.java:99)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:540)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:204)
	at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:596)
	at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$2(GrpcServerImpl.java:647)
FAILED: Build did NOT complete successfully (0 packages loaded)
(tftf) zhiyuanma@ZhiyuanMas-MacBook-Pro mediapipe % $ bazel build -c opt --define MEDIAPIPE_DISABLE_GPU=1 \
  --distdir=./bazel_skylib/ \
  --repository_cache=./bazel_skylib/ \
  --keep_going \
mediapipe/examples/desktop/multi_hand_tracking:multi_hand_tracking_cpu

So I don't know what's going wrong. Maybe I specified a wrong path to my caches package? Or in fact, I got blocked in the next step?
BTW, I found so many Chinese workers worrying about the network. Great Firewall is so TROUBLESOME!