Too strict looking for config paths, difficult to combine different installs

[osrf-migration]

Original report (archived issue) by Louise Poubel (Bitbucket: chapulina, GitHub: chapulina).

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Prerequisites

• [ X ] Put an X between the brackets on this line if you have done all of the following:
  • Checked the Q&A board for common solutions: http://answers.gazebosim.org
  • Checked that your issue isn't already filed.
  • Checked that there is not already an Ignition package that provides the described functionality: https://ignitionrobotics.org/libs

Description

By default, ign-tools will look at its own installed path for yaml config files of other libraries. This works fine when all libraries have been installed from debs, because they all end up under the same directory structure under /usr. But it fails for example when one was installed from debs and the other was installed from source to /usr/local or some other custom path.

Steps to Reproduce

1. Install ign-tools from debs: sudo apt install libignition-tools-dev
2. Build another library from source, such as ign-msgs.
3. Try to run ign msg, and ign-tools won't be able to find the msg command.

Expected behavior:

Ignition tools should find the library, either by default, or with some documented configuration steps.

Actual behavior:

The command can't be found.

Additional Information

This discussion started on issue #2, look there for more context.

A partial solution is to set the IGN_CONFIG_PATH variable at runtime pointing at the library to be found. This works well if you only need to find libraries in a single path, but doesn't work for several libraries installed to different paths, because IGN_CONFIG_PATH only accepts a single path.

Another workaround is to use symlinks as described here, for example:

mkdir ~/.ignition/tools/configs -p
cd ~/.ignition/tools/configs/
ln -s ~/ws/install/ignition-transport6/share/ignition/transport6.yaml .
ln -s ~/ws/install/ignition-gui1/share/ignition/gui1.yaml .
...
export IGN_CONFIG_PATH=$HOME/.ignition/tools/configs

[osrf-migration]

Original comment by Louise Poubel (Bitbucket: chapulina, GitHub: chapulina).

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• Edited issue description

[scpeters]

multiple paths can now be specified in IGN_CONFIG_PATH using the : delimiter as of BitBucket pull request 13

[chapulina]

Ohh I think we can remove a bunch of troubleshooting sections then, like this one:

https://github.com/ignitionrobotics/ign-fuel-tools/#known-issue-of-command-line-tools