restore old behaviour as the default for package variance

[sbcl.git] / doc / manual / beyond-ansi.texinfo

diff --git a/doc/manual/beyond-ansi.texinfo b/doc/manual/beyond-ansi.texinfo
index b365498..348208c 100644 (file)
--- a/doc/manual/beyond-ansi.texinfo
+++ b/doc/manual/beyond-ansi.texinfo
@@ -58,6 +58,9 @@ has been specified. Different packages can use same local nickname for
 different global names, or different local nickname for same global
 name.
 
+Symbol @code{:package-local-nicknames} in @code{*features*} denotes the
+support for this feature.
+
 @findex @cl{defpackage}
 @defmac @cl{defpackage} name [[option]]* @result{} package
 
@@ -91,6 +94,19 @@ Example:
 @include fun-sb-ext-add-package-local-nickname.texinfo
 @include fun-sb-ext-remove-package-local-nickname.texinfo
 
+@node  Package Variance
+@comment  node-name,  next,  previous,  up
+@section Package Variance
+
+Common Lisp standard specifies that ``If the new definition is at
+variance with the current state of that package, the consequences are
+undefined;'' SBCL by default signals a full warning and retains as
+much of the package state as possible.
+
+This can be adjusted using @code{sb-ext:*on-package-variance*}:
+
+@include var-sb-ext-star-on-package-variance-star.texinfo
+
 @node  Garbage Collection
 @comment  node-name,  next,  previous,  up
 @section Garbage Collection