Merge branch 'stable'

Author: mpilgrem

doc/build_command.md

@@ -205,12 +205,8 @@ command line only) with:
 stack build --flag *:[-]<flag_name>
 ~~~
 
-!!! note
-
-    Currently you needs to list all of your modules that interpret flags in the
-    `other-modules` section of a Cabal file. Cabal (the tool) has a different
-    behavior currently and doesn't require that the modules be listed. This may
-    change in a future release.
+In order to set a Cabal flag for a GHC boot package, the package must be
+specified as an extra-dep.
 
 ### `--[no-]force-dirty` flag
 

doc/ghci.md

@@ -97,6 +97,24 @@ command:
 stack ghci --package lens
 ~~~
 
+## Specifying Cabal flags
+
+`--flag <package_name>:[-]<flag_name>` sets (or unsets) the specified Cabal flag
+for the specified package.
+
+This option can be specified multiple times to set (or unset) multiple Cabal
+flags.
+
+The same Cabal flag name can be set (or unset) for multiple packages with:
+
+~~~text
+--flag *:[-]<flag_name>
+~~~
+
+In order to set a Cabal flag for a GHC boot package, the package must either be
+an extra-dep or the package version must be specified with the `--package`
+option.
+
 ## Running plain GHCi
 
 `stack ghci` always runs GHCi configured to load code from packages in your

doc/yaml_configuration.md

@@ -241,18 +241,23 @@ the configuration means "extra-deps packages in directories
 
 Default: `{}`
 
-Command line equivalent (takes precedence): `stack build --flag` option
+Command line equivalent (takes precedence):
+[`stack build --flag`](build_command.md#-flag-option) option
 
-Flags can be set for each package separately. For example:
+Cabal flags can be set for each package separately. For example:
 
 ~~~yaml
 flags:
   package-name:
     flag-name: true
 ~~~
 
-If a specified flag is different than the one specified for a snapshot package,
-then the snapshot package will automatically be promoted to be an extra-dep.
+If a specified Cabal flag for a package included directly in a snapshot is
+different to the Cabal flag specified for that package in the snapshot, then the
+package will automatically be promoted to be an extra-dep.
+
+In order to set a Cabal flag for a GHC boot package, the package must be
+specified as an extra-dep.
 
 ### drop-packages