I don't know if this is caused by an incomplete download or corrupt git repo. The tag I used to download is: android-10.0.0_r1.
Here is the error:
[100% 135/135] out/soong/.bootstrap/bin/soong_build out/soong/build.ninja
FAILED: out/soong/build.ninja
out/soong/.bootstrap/bin/soong_build -t -l out/.module_paths/Android.bp.list -b out/soong -n out -d out/soong/build.ninja.d -globFile out/soong/.bootstrap/build-globs.ninja -o out/soong/build.ninja Android.bp
error: external/icu/tools/srcgen/currysrc/Android.bp:42:1: "currysrc" depends on undefined module "jopt-simple-4.9"
00:16:17 soong bootstrap failed with: exit status 1