Document environment variables used for advanced configuration

docs/configuration.md

@@ -0,0 +1,13 @@
+# Configuration
+
+## Basic options
+
+conda-libmamba-solver is a _solver plugin_ and can be configured with the same settings as the classic solver. This is usually done via the `conda config` subcommand. Read the [conda configuration docs](https://docs.conda.io/projects/conda/en/stable/configuration.html) and check for the general solver options there.
+
+## Advanced options
+
+Additionally, conda-libmamba-solver can be further configured via special environment variables.
+We do not recomment using these options in production environments. Their behavior might change in the future, or they can be entirely removed without prior notice.
+
+* `CONDA_LIBMAMBA_SOLVER_MAX_ATTEMPTS`: Maximum number of attempts to find a solution. By default, this is set to the number of installed packages in the environment. In commands that involve a large number of changes in a large environment, it can take a bit to relax the constraints enough to find a solution. This option can be used to reduce the number of attempts and "give up" earlier.
+* `CONDA_LIBMAMBA_SOLVER_NO_CHANNELS_FROM_INSTALLED`: Do not inject the channels defined in the installed packages in the configured index.

docs/index.md

@@ -11,6 +11,7 @@ Start here if you want a faster conda:
 :maxdepth: 1
 getting-started
 subcommands
+configuration
 libmamba-vs-classic
 performance
 faq

news/359-env-var-docs

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* Document environment variables used for advanced configuration. (#349)
+
+### Other
+
+* <news item>