reboot loses addPluginSbtFile settings

[jastice]

• I've read the CONTRIBUTING guidelines

steps

To be able to use the addPluginSbtFile option, I start the user's sbt shell in IntelliJ with the -Dsbt.version=1.2.0 parameter.

This causes the warning on startup:

[warn] sbt version mismatch, current: 1.2.0, in build.properties: "1.1.6", use 'reboot' to use the new value.

problem

Actually doing a reboot from the shell will then apparently lose the the injected settings, causing the reboot to fail because of the missing command added by the injected plugin. The warning still appears, however:

[IJ]sbt:untitled5> reboot
[warn] sbt version mismatch, current: 1.2.0, in build.properties: "1.1.6", use 'reboot' to use the new value.
[info] Loading settings for project global-plugins from idea.sbt,plugins.sbt ...
[info] Loading global plugins from /Users/jast/.sbt/1.0/plugins
[info] Updating ProjectRef(uri("file:/Users/jast/.sbt/1.0/plugins/"), "global-plugins")...
[info] Done updating.
[info] Loading project definition from /Users/jast/playspace/untitled5/project
[info] Updating ProjectRef(uri("file:/Users/jast/playspace/untitled5/project/"), "untitled5-build")...
[info] Done updating.
[info] Loading settings for project untitled5 from build.sbt ...
[info] Set current project to untitled5 (in build file:/Users/jast/playspace/untitled5/)
[error] Not a valid command: idea-shell (similar: shell, oldshell)
[error] Not a valid project ID: idea-shell
[error] Expected ':'
[error] Not a valid key: idea-shell
[error] idea-shell
[error]           ^

Process finished with exit code 1

expectation

• Ideally, reboot should work with the added plugins intact.
• Independently, an option to disable the warning would be good to avoid misleading and annoying users.

notes

sbt version: 1.2.0

Follow-up to #4211

[NicolasRouquette]

I experienced the same problem manifestation with intellij.
After some experiments, it seems to me that sbt doesn't actually recognizes the --addPluginSbtFile=<file> option as I've described here: https://youtrack.jetbrains.com/issue/IDEA-199224

I wonder if there is a regression bug w.r.t. this new option.
Even outside of intellij, I haven't been able to get this option to work as intended.