icedtea6 fails to bootstrap on Fedora 17/18

[Stefan Ring]

compile:
    [javac] Compiling 2545 source files to
/home/sr/staging/staging-build/icedtea6/openjdk.build-ecj/jaxws/build/classes
    [javac] ----------
    [javac] 1. ERROR in
/xfs/staging/staging-build/icedtea6/openjdk-ecj/jdk/src/share/classes/com/sun/net/httpserver/HttpsConfigurator.java
(at line 112)
    [javac]     params.setSSLParameters
(getSSLContext().getDefaultSSLParameters());
    [javac]                                              ^^^^^^^^^^^^^^^^^^^^^^^
    [javac] The method getDefaultSSLParameters() is undefined for the
type SSLContext
    [javac] ----------
    [javac] ----------
    [javac] 2. ERROR in
/xfs/staging/staging-build/icedtea6/openjdk-ecj/jdk/src/share/classes/sun/net/httpserver/SSLStreams.java
(at line 82)
    [javac]     engine.setSSLParameters (sslParams);
    [javac]            ^^^^^^^^^^^^^^^^
    [javac] The method setSSLParameters(SSLParameters) is undefined
for the type SSLEngine
    [javac] ----------
    [javac] 2 problems (2 errors)

BUILD FAILED
/xfs/staging/staging-build/icedtea6/openjdk-ecj/jaxws/build.xml:136:
Compile failed; see the compiler error output for details.

Total time: 52 seconds
make[4]: *** [all] Error 1
make[4]: Leaving directory
`/xfs/staging/staging-build/icedtea6/openjdk-ecj/jaxws/make'
make[3]: *** [jaxws-build] Error 2
make[3]: Leaving directory `/xfs/staging/staging-build/icedtea6/openjdk-ecj'
make[2]: *** [build_product_image] Error 2
make[2]: Leaving directory `/xfs/staging/staging-build/icedtea6/openjdk-ecj'
make[1]: *** [jdk_only] Error 2
make[1]: Leaving directory `/xfs/staging/staging-build/icedtea6/openjdk-ecj'
make: *** [stamps/icedtea-ecj.stamp] Error 2

Has anyone ever investigated what causes this? I cannot find the error
message on google. The same build works on Ubuntu quantal whose system
Java is also no longer Java 6. No exotic configure switches used:

--disable-docs --with-jdk-home=/usr/lib/jvm/java-1.5.0/gcj

There shouldn't be a significant difference between these two:

Ubuntu quantal:
$ /usr/lib/jvm/java-1.5.0-gcj/bin/java -version
java version "1.5.0"
gij (GNU libgcj) version 4.7.2

Fedora 17:
$ /usr/lib/jvm/java-1.5.0-gcj/bin/java -version
java version "1.5.0"
gij (GNU libgcj) version 4.7.2 20120921 (Red Hat 4.7.2-2)

ecj is much more recent on Fedora apparently:

Ubuntu quantal $ ecj -version:
Eclipse Java Compiler 0.972_R35x, 3.5.1 release, Copyright IBM Corp
2000, 2009. All rights reserved.
Fedora 17 $ ecj -version
Eclipse Compiler for Java(TM) v20120814-155456, 3.8.2, Copyright IBM
Corp 2000, 2012. All rights reserved.

The only way I was able to get icedtea6 to build on Fedora 17 was to
copy a binary j2sdk-image over from CentOS 6 and use that as jdk-home.