the host config can *only* be set as global config

[sbarthelemy]

The only way to set the host config is by marking a single config as host="true" in ~/.qi/qibuild.xml.

This makes the option a global.

Imagine you want to cross-compile two branches (say master and release-2.0) each branch using its own version of the desktop and robot toolchain. You end up with 4 configs:

linux64-master
linux64-release2.6
atom-master
atom-release2.6

but you cannot build for atom-release2.6 and atom-master in parallel since they both require a different host config. (actually you cannot build for linux64-master and linux64-release2.6 in parallel either for the same reason).

having a global "default host config" is not bad per se, but there should be other ways to change that at a narrower scope. For instance

• get the info from command-line option
• get the info from an environment variable
• let each config in ~/.qi/qibuild.xml set its own host config.

[dmerejkowsky]

let each config in ~/.qi/qibuild.xml set its own host config.

Not sure whay you mean by that. Care to elaborate ?

[sbarthelemy]

currently we have a list of configs an one of them is tagged as the host config.

For instance here is the set of configs I use:

<config host="true" name="master-linux64">
  <toolchain>master-linux64</toolchain>
</config>
<config name="master-nao">
  <toolchain>master-atom</toolchain>
  <profiles>
    <profile>nao</profile>
  </profiles>
</config>
<config name="release-2.6-linux64">
  <toolchain>release-2.6-linux64</toolchain>
</config>
<config name="release-2.6-nao">
  <toolchain>release-2.6-atom</toolchain>
  <profiles>
    <profile>nao</profile>
  </profiles>
</config>

master-linux64 is the host config. It is rightfully used when cross-compiling for master-nao.
But when cross-compiling for release-2.6-nao, I should use release-2.6-linux64 as the host config.

As a consequence, I need to change the host config each time I switch between release-2.6 and master.

Since the config is global, that also means I cannot concurrently cross-compile for both master-nao and release-2.6-nao (even in two distinct worktrees).

An alternative implementation would be something like

<config name="master-linux64">
  <toolchain>master-linux64</toolchain>
</config>
<config name="master-nao" host_config="master-linux64">
  <toolchain>master-atom</toolchain>
  <profiles>
    <profile>nao</profile>
  </profiles>
</config>
<config name="release-2.6-linux64">
  <toolchain>release-2.6-linux64</toolchain>
</config>
<config name="release-2.6-nao" host_config="release-2.6-linux64">
  <toolchain>release-2.6-atom</toolchain>
  <profiles>
    <profile>nao</profile>
  </profiles>
</config>

Another solution would be to let the user pass the host config name as a command line argument

qibuild make-host-tools --host-config=release-2.6-linux64
qibuild configure --host-config=release-2.6-linux64 -c release-2.6-nao
qibuild make -c release-2.6-nao

Or to provide a way to use different config file (one per worktree) or passed from command-line argument.

Another "solution" would be to drop the host config feature and require host tools to be in the toolchain.