On systems where `/bin/sh` is a POSIX-compliant shell (such as Dash without the hobbling of `$LINENO` that some distros inflict on it), Autoconf will use `/bin/sh` as its `configure` script interpreter. Bashisms in `configure.ac` thus lead to shell errors at runtime. The most common such Bashism is the use of the `==` operator with the `test` built-in.
SQLite's `configure.ac` has one such occurrence of the `==` operator, which causes Dash to emit errors of the form:
./configure: 12664: test: unexpected operator
Please apply this patch to eliminate the Bashism:
```
diff -Naur a/configure.ac b/configure.ac
--- a/configure.ac 2020-06-18 14:35:12.000000000 +0000
+++ b/configure.ac 2020-07-06 21:22:52.742873150 +0000
@@ -569,7 +569,7 @@
# See whether we should use the amalgamation to build
AC_ARG_ENABLE(amalgamation, AC_HELP_STRING([--disable-amalgamation],
[Disable the amalgamation and instead build all files separately]))
-if test "${enable_amalgamation}" == "no" ; then
+if test "${enable_amalgamation}" = "no" ; then
USE_AMALGAMATION=0
fi
AC_SUBST(USE_AMALGAMATION)
```