diff --git a/lib/node_modules/@stdlib/_tools/repl-txt/rules/doctest/lib/main.js b/lib/node_modules/@stdlib/_tools/repl-txt/rules/doctest/lib/main.js
index 64b64e6151ee..4cadcb83661c 100644
--- a/lib/node_modules/@stdlib/_tools/repl-txt/rules/doctest/lib/main.js
+++ b/lib/node_modules/@stdlib/_tools/repl-txt/rules/doctest/lib/main.js
@@ -25,6 +25,7 @@ var dirname = require( 'path' ).dirname;
 var replace = require( '@stdlib/string/replace' );
 var namespace = require( '@stdlib/namespace' );
 var hasOwnProp = require( '@stdlib/assert/has-own-property' );
+var copy = require( '@stdlib/utils/copy' );
 var compareValues = require( '@stdlib/_tools/doctest/compare-values' );
 
 
@@ -135,9 +136,12 @@ function main( context ) {
 						expected.push( current.output );
 						match = code.match( RE_ASSIGNMENT );
 						if ( match && match[ 1 ] ) {
-							actual.push( scope[ match[ 1 ] ] );
+							// Snapshot the value, as accumulator-style examples may return
+							// a shared, mutable reference (e.g., a stateful output array)
+							// that later statements overwrite in place:
+							actual.push( copy( scope[ match[ 1 ] ] ) );
 						} else {
-							actual.push( out );
+							actual.push( copy( out ) );
 						}
 					}
 				} catch ( err ) {
diff --git a/package.json b/package.json
index 00fe02e17211..8be468eb4ff8 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,7 @@
     "clean": "make clean",
     "check-deps": "make check-deps",
     "check-licenses": "make check-licenses",
-    "postinstall": "tools/scripts/apply_patches"
+    "postinstall": "if test -f tools/scripts/apply_patches; then tools/scripts/apply_patches; fi"
   },
   "homepage": "https://github.com/stdlib-js/stdlib",
   "repository": {