Document the --incompatible_show_all_print_messages flag
@@ -43,6 +43,9 @@ guarded behind flags in the current release:
* [Dictionary literal has no duplicates](#dictionary-literal-has-no-duplicates)
* [New actions API](#new-actions-api)
* [Checked arithmetic](#checked-arithmetic)
+* [Glob tracking](#glob-tracking)
+* [Print statements](#print-statements)
+
### Set constructor
@@ -293,6 +296,7 @@ All integers are stored using signed 32 bits.
* Flag: `--incompatible_checked_arithmetic`
* Default: `true`
+
### Glob tracking
When set, glob tracking is disabled. This is a legacy feature that we expect has
@@ -301,4 +305,17 @@ no user-visible impact.
* Flag: `--incompatible_disable_glob_tracking`
* Default: `false`
+
+### Print statements
+
+`print` statements in Skylark code are supposed to be used for debugging only.
+Messages they yield used to be filtered out so that only messages from the same
+package as the top level target being built were shown by default (it was
+possible to override by providing, for example, `--output_filter=`). That made
+debugging hard. When the flag is set to true, all print messages are shown in
+the console without exceptions.
+
+* Flag: `--incompatible_show_all_print_messages`
+* Default: `true`
+
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