build: fix --enable-single-binary=hardlinks with dash

With dash as /bin/sh, you get the error
```
checking for sys/capability.h... yes
./configure: 95775: test: no: unexpected operator
checking for working fork... yes
```

* configure.ac: Use '=' in test for equality, not '==',
for POSIX shell compatibility.
* NEWS: Mention the build fix.

diff --git a/NEWS b/NEWS
index 5fbf1bdc5717c3813a683a5bb85f2b04b5e447b0..a696b636f64259f83669285a0fa14215a536e631 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,11 @@ GNU coreutils NEWS                                    -*- outline -*-
   'kill --help' now has links to valid anchors in the html manual.
   [bug introduced in coreutils-9.10]
 
+** Build-related
+
+  ./configure --enable-single-binary=hardlinks is now supported on systems
+  with dash as the system shell at /bin/sh.
+
 
 * Noteworthy changes in release 9.10 (2026-02-04) [stable]
 

diff --git a/configure.ac b/configure.ac
index ae00396ec42e91952b74ed4021d2c961ff4f57c7..2da648987c2d81d291d93858d5dd82ae045cb567 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -134,7 +134,7 @@ if test "$gl_single_binary" = 'symlinks' ||
   fi
 fi
 AM_CONDITIONAL([SINGLE_BINARY], [test "$gl_single_binary" != no])
-AM_CONDITIONAL([SINGLE_BINARY_HARD], [test "$gl_single_binary" == hardlinks])
+AM_CONDITIONAL([SINGLE_BINARY_HARD], [test "$gl_single_binary" = hardlinks])
 
 AC_ARG_ENABLE([bold-man-page-references],
   [AS_HELP_STRING([--disable-bold-man-page-references],