Getting Help

Programming is difficult, and programming at the level needed for autonomous systems is even harder. Every developer write bugs, encounters confusing errors, and gets stuck in countless other ways. With time you’ll learn not how to write better code, but also how to effectively get help when you’re stuck.

You should always try to solve problems yourself using the internet, documentation, etc before asking others. This not only shows respect for your peers’ time (who likely also have their own problems) but will lead you to learn more. In other words, teach yourself to fish rather than asking for fish.

Check your sanity

A great first move is to take a step back and think about what you’re trying to do and if it makes sense.

Ask yourself the following questions:

• Are you running the latest code? Have you pulled from git lately (including submodules) and updated your system packages?

  • Be sure to back up / commit any changes to a branch

  • To reset to the latest code from github run git fetch origin and then git checkout origin/master -B master

  • Be sure to initialize and update all submodules as well with git submodule update --init --recursive.

• If the error says exactly how to fix it, have you tried that?

• Is your system setup correctly as described in the Getting Started Guide?

• Have you blindly copy-pasted/ran things from the internet? If so, do you know why? Do you know what it’s doing?

• Could you be trying to use something that is outdated / deprecated?

• Have you tried rebooting your system or running it again?

Search these docs

You may have noticed that these docs have a search bar. If you want to learn about a topic, try putting in some keywords related to your topic or finding a docs page in the table of contents. The search bar will also help you to find related code to the problem you may be encountering, as it can search through the entire software reference.

You may find the Glossary especially useful.

View the docs on related classes/methods

Although you may be developing a new system/class/method (or not!), finding the documentation on classes/methods related to what you’re building can be very helpful.

For example, let’s say you’re working with the Passive Sonar system. Try finding some of the MIL-specific classes/methods you’re working with (such as mil_passive_sonar.TxHydrophonesClient) and then viewing the docs on those classes/methods in our reference docs.

Search the code with grep

Perhaps the most useful command for a programmer is grep. Grep can search quickly through files for a particular pattern or string. git grep is an even faster way to search everything in a git repository (such as the MIL repo).

For example, if you see an error DVL: error on write, you can run:

~/catkin_ws/src/mil$ git grep "DVL: error on write"
SubjuGator/drivers/sub8_rdi_dvl/include/rdi_explorer_dvl/driver.hpp: \
    ROS_ERROR_THROTTLE(0.5, "DVL: error on write: %s; dropping heartbeat", exc.what());

And see the exact source file where this error comes from.

Likewise, if you want to learn how to use a function, you can search the code for examples of it being used.

Search the internet

If your problem is not MIL-specific (issue with Linux, ROS, C++, etc), someone has most likely had the same problem and written about it on the internet. You’ll be surprised how often you can fix your issue by Googling the error.

Search Slack

Someone may have already asked a similar question on Slack. Try searching there.

Ask for Help

If you made decent efforts to follow the above steps to figure things out on your own, now it is time to ask for help!

In order for people to be able to understand your issue, please include:

• Precisely what circumstances brought about the error (command, version of software, etc)

• What you are trying to do / achieve

• What steps you have already taken to debug

• The exact code in question (push it to a github branch if it is your changes)

File an issue

If you believe you have discovered an issue with something that should be working, it may be appropriate to file an issue on Github.

Ask on slack / in-person

If your issue regards code that you are developing or might be specific to your use case, come by office hours or ask around in the #software channel on slack.