I got a build error on a freshly installed macOS Sequoia 15.4 with Xcode 16.3 and brew-installed autoconf:

Compiling up to 94 files for jdk.xml.dom
sed: RE error: illegal byte sequence
make[3]: *** [/mrserb/jdk/build/macosx-aarch64-server-release/jdk/modules/java.xml.crypto/com/sun/org/apache/xml/internal/security/resource/xmlsecurity_de.properties] Error 1
make[3]: *** Deleting file `/mrserb/jdk/build/macosx-aarch64-server-release/jdk/modules/java.xml.crypto/com/sun/org/apache/xml/internal/security/resource/xmlsecurity_de.properties'
make[2]: *** [java.xml.crypto-java] Error 2
make[2]: *** Waiting for unfinished jobs...

This looks similar to the previously reported issue: JDK-8065365, but the suggested workaround (LC_ALL=C) does not work in this case. (tested on zsh and bash)