diff --git a/asdf.asd b/asdf.asd
index 9c41bd3e4d81dafc3065f5367f9ab673f740bc36..bd13576cf93a98a4bd77caa1c58efb6a892899d6 100644
--- a/asdf.asd
+++ b/asdf.asd
@@ -74,7 +74,7 @@
   :licence "MIT"
   :description "Another System Definition Facility"
   :long-description "ASDF builds Common Lisp software organized into defined systems."
-  :version "2.33" ;; to be automatically updated by make bump-version
+  :version "2.33.1" ;; to be automatically updated by make bump-version
   :depends-on ()
   #+asdf3 :encoding #+asdf3 :utf-8
   ;; For most purposes, asdf itself specially counts as a builtin system.
diff --git a/header.lisp b/header.lisp
index 511becf318372bf7d86d8ee5510fc6ba9189bd78..477aa2b60014c3993d4f1a0f33cf27b07a2fa764 100644
--- a/header.lisp
+++ b/header.lisp
@@ -1,5 +1,5 @@
 ;;; -*- mode: Common-Lisp; Base: 10 ; Syntax: ANSI-Common-Lisp -*-
-;;; This is ASDF 2.33: Another System Definition Facility.
+;;; This is ASDF 2.33.1: Another System Definition Facility.
 ;;;
 ;;; Feedback, bug reports, and patches are all welcome:
 ;;; please mail to <asdf-devel@common-lisp.net>.
diff --git a/operation.lisp b/operation.lisp
index ae4972ada3eb464cfc0a77cd0c0db5e80dbd76be..ca6c5c09a94679b9d957fd09f675c5e672899b4f 100644
--- a/operation.lisp
+++ b/operation.lisp
@@ -6,7 +6,7 @@
   (:use :asdf/common-lisp :asdf/driver :asdf/upgrade)
   (:export
    #:operation
-   #:operation-original-initargs ;; backward-compatibility only. DO NOT USE.
+   #:operation-original-initargs #:original-initargs ;; backward-compatibility only. DO NOT USE.
    #:build-op ;; THE generic operation
    #:*operations* #:make-operation #:find-operation #:feature))
 (in-package :asdf/operation)
diff --git a/uiop/lisp-build.lisp b/uiop/lisp-build.lisp
index 789f6d1aab7c15e9cd3167663dea816e43ca8e35..641843df4b4524ff280b179fb417dfde1e6797e7 100644
--- a/uiop/lisp-build.lisp
+++ b/uiop/lisp-build.lisp
@@ -87,7 +87,7 @@ Note that ASDF ALWAYS raises an error if it fails to create an output file when
     (deftype sb-grovel-unknown-constant-condition ()
       '(and style-warning (satisfies sb-grovel-unknown-constant-condition-p))))
 
-  (defvar *uninteresting-conditions*
+  (defvar *usual-uninteresting-conditions*
     (append
      ;;#+clozure '(ccl:compiler-warning)
      #+cmu '("Deleting unreachable code.")
@@ -99,7 +99,7 @@ Note that ASDF ALWAYS raises an error if it fails to create an output file when
        #+sb-eval sb-kernel:lexical-environment-too-complex
        sb-kernel:undefined-alien-style-warning
        sb-grovel-unknown-constant-condition ; defined above.
-       ;; sb-ext:implicit-generic-function-warning ; Controversial. Let's allow it by default.
+       sb-ext:implicit-generic-function-warning ;; Controversial.
        sb-int:package-at-variance
        sb-kernel:uninteresting-redefinition
        ;; BEWARE: the below four are controversial to include here.
@@ -108,6 +108,9 @@ Note that ASDF ALWAYS raises an error if it fails to create an output file when
        sb-kernel:redefinition-with-defmethod
        sb-kernel::redefinition-with-defmacro) ; not exported by old SBCLs
      '("No generic function ~S present when encountering macroexpansion of defmethod. Assuming it will be an instance of standard-generic-function.")) ;; from closer2mop
+    "A suggested value to which to set or bind *uninteresting-conditions*.")
+
+  (defvar *uninteresting-conditions* '()
     "Conditions that may be skipped while compiling or loading Lisp code.")
   (defvar *uninteresting-compiler-conditions* '()
     "Additional conditions that may be skipped while compiling Lisp code.")
diff --git a/uiop/run-program.lisp b/uiop/run-program.lisp
index b43877c328e122f31d3ffcf684362d5b1c8e9022..7d6a10f2844ed418d84fd19343bb2d9b891f9a5d 100644
--- a/uiop/run-program.lisp
+++ b/uiop/run-program.lisp
@@ -213,15 +213,22 @@ by /bin/sh in POSIX"
                        &allow-other-keys)
     "Run program specified by COMMAND,
 either a list of strings specifying a program and list of arguments,
-or a string specifying a shell command (/bin/sh on Unix, CMD.EXE on Windows);
-have its output processed by the OUTPUT processor function
-as per SLURP-INPUT-STREAM,
-or merely output to the inherited standard output if it's NIL.
+or a string specifying a shell command (/bin/sh on Unix, CMD.EXE on Windows).
+
 Always call a shell (rather than directly execute the command)
 if FORCE-SHELL is specified.
-Issue an error if the process wasn't successful unless IGNORE-ERROR-STATUS
-is specified.
-Return the exit status code of the process that was called.
+
+Signal a SUBPROCESS-ERROR if the process wasn't successful (exit-code 0),
+unless IGNORE-ERROR-STATUS is specified.
+
+If OUTPUT is either NIL or :INTERACTIVE, then
+return the exit status code of the process that was called.
+if it was NIL, the output is discarded;
+if it was :INTERACTIVE, the output and the input are inherited from the current process.
+
+Otherwise, the output will be processed by SLURP-INPUT-STREAM,
+using OUTPUT as the first argument, and return whatever it returns,
+e.g. using :OUTPUT :STRING will have it return the entire output stream as a string.
 Use ELEMENT-TYPE and EXTERNAL-FORMAT for the stream passed to the OUTPUT processor."
     (declare (ignorable ignore-error-status element-type external-format))
     #-(or abcl allegro clisp clozure cmu cormanlisp ecl gcl lispworks mcl sbcl scl xcl)
diff --git a/upgrade.lisp b/upgrade.lisp
index 36a4ef226a9613ba527faf9d8b07877f64ff8519..1ffa5f3ca12980aab06e3c720ba3e9433ff3d759 100644
--- a/upgrade.lisp
+++ b/upgrade.lisp
@@ -52,7 +52,7 @@ You can compare this string with e.g.: (ASDF:VERSION-SATISFIES (ASDF:ASDF-VERSIO
          ;; "3.4.5.67" would be a development version in the official upstream of 3.4.5.
          ;; "3.4.5.0.8" would be your eighth local modification of official release 3.4.5
          ;; "3.4.5.67.8" would be your eighth local modification of development version 3.4.5.67
-         (asdf-version "2.33")
+         (asdf-version "2.33.1")
          (existing-version (asdf-version)))
     (setf *asdf-version* asdf-version)
     (when (and existing-version (not (equal asdf-version existing-version)))
diff --git a/version.lisp-expr b/version.lisp-expr
index 8623b8dcdea306761f2371a8d9b8a92b004b8911..649b5df6c622588492c23d7d0b38d55b09c7664a 100644
--- a/version.lisp-expr
+++ b/version.lisp-expr
@@ -1 +1 @@
-"2.33"
+"2.33.1"