Fix top-level ns-3 test wrapper to avoid mtp.h build failures

[Copilot]

The documented ./scripts/build.sh -t ns3 devices-point-to-point flow was not reliable from the repo root. In practice, the wrapper could fall into the SimAI extern ns-3 build path and trigger unrelated mtp test compilation, surfacing ns3/mtp.h errors that are not part of the devices-point-to-point suite.

• What changed

  • Add and harden the top-level -t|--test path in scripts/build.sh
  • Reject ./scripts/build.sh -c ns3 <suite> and point users to the correct test entrypoint
  • Normalize point-to-point to the actual suite name devices-point-to-point

• ns-3 source selection

  • Run ns-3 tests from the repository submodule source tree:
    • ns-3-alibabacloud/simulation
  • Stop using the copied SimAI extern tree for the test wrapper
  • Auto-initialize ns-3-alibabacloud if the submodule is missing locally

• Avoid unrelated mtp failures

  • Configure only the modules needed for the point-to-point test path:
    • core,network,stats,point-to-point,test
  • Skip the broader module set that can pull in mtp and fail on ns3/mtp.h
  • Run test.py with --no-build after the targeted build step

• Docs

  • Update the root README to document the correct top-level command and clarify that this suite runs through the ns-3 test framework, not the SimAI ns-3 compile flow

Example:

./scripts/build.sh -t ns3 devices-point-to-point

Invalid usage is now handled explicitly:

./scripts/build.sh -c ns3 devices-point-to-point
# ns3 compile mode does not accept a test suite.
# Use ./scripts/build.sh -t ns3 devices-point-to-point instead.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[tianhao909]

转@wtl0000的评论：
这个方案./scripts/build.sh -t ns3 devices-point-to-point，我是在simai文件夹下运行，但是这样无法运行，我运行的是./scripts/build.sh -c ns3 devices-point-to-point，但是报错找不到mtp.h，我在github和我自己的文件上都找不到这个文件，这个方案为Example:
./scripts/build.sh -t ns3 devices-point-to-point
我将build.sh进行了更新，运行了./scripts/build.sh -t ns3 devices-point-to-point，出错

[wtl0000]

我按照本方案的build.sh进行修改运行，但还是有

找不到mtp.h这个文件，这个文件在github上好像也没有