The alpine builders print out a warning about sched_getaffinity() not working.
This causes the version check for the boot jdk to fail.
Patch the command to determine the version number to ignore any errors and warnings.

--- old/make/autoconf/boot-jdk.m4
+++ new/make/autoconf/boot-jdk.m4
@@ -74,7 +74,7 @@
           BOOT_JDK_FOUND=no
         else
           # Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
-          BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" $USER_BOOT_JDK_OPTIONS -version 2>&1 | $HEAD -n 1`
+          BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" $USER_BOOT_JDK_OPTIONS -version 2>&1 | $GREP version | $HEAD -n 1`
           if [ [[ "$BOOT_JDK_VERSION" =~ "Picked up" ]] ]; then
             AC_MSG_NOTICE([You have _JAVA_OPTIONS or JAVA_TOOL_OPTIONS set. This can mess up the build. Please use --with-boot-jdk-jvmargs instead.])
             AC_MSG_NOTICE([Java reports: "$BOOT_JDK_VERSION".])