diff --git a/MANIFEST.MF b/MANIFEST.MF
index fec577b..7d260b6 100644
--- a/MANIFEST.MF
+++ b/MANIFEST.MF
@@ -1,10 +1,5 @@
 Manifest-Version: 1.0
 Bundle-SymbolicName: org.eclipse.jdt.core.compiler.batch
-Archiver-Version: Plexus Archiver
-Built-By: genie.releng
-Bundle-ManifestVersion: 2
-Bundle-Vendor: Eclipse.org
-Main-Class: org.eclipse.jdt.internal.compiler.batch.Main
 Export-Package: org.eclipse.jdt.core,org.eclipse.jdt.core.compiler,org
  .eclipse.jdt.internal.antadapter;x-internal:=true,org.eclipse.jdt.int
  ernal.compiler;x-internal:=true,org.eclipse.jdt.internal.compiler.apt
@@ -23,8 +18,12 @@ Export-Package: org.eclipse.jdt.core,org.eclipse.jdt.core.compiler,org
  -internal:=true,org.eclipse.jdt.internal.compiler.tool;x-internal:=tr
  ue
 Bundle-Name: Eclipse Compiler for Java(TM)
-Bundle-Version: 3.13.0.v20170516-1929
+Bundle-Version: 3.18.0.v20190522-0428
 Bundle-ClassPath: .
-Created-By: Apache Maven
-Build-Jdk: 1.8.0_121
+Built-By: genie.releng
+Bundle-ManifestVersion: 2
+Bundle-Vendor: Eclipse.org
+Created-By: Apache Maven 3.5.4
+Build-Jdk: 1.8.0_192
+Main-Class: org.eclipse.jdt.internal.compiler.batch.Main
 
diff --git a/ecj-3.29.0.pom b/ecj-3.18.0.pom
similarity index 92%
rename from ecj-3.29.0.pom
rename to ecj-3.18.0.pom
index 537fbeb..b739824 100644
--- a/ecj-3.29.0.pom
+++ b/ecj-3.18.0.pom
@@ -16,7 +16,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.eclipse.jdt</groupId>
   <artifactId>ecj</artifactId>
-  <version>3.29.0</version>
+  <version>3.18.0</version>
   <description>Eclipse Compiler for Java(TM)</description>
   <name>Eclipse Compiler for Java(TM)</name>
   <url>http://www.eclipse.org/jdt</url>
@@ -36,7 +36,7 @@
     <url>https://bugs.eclipse.org/</url>
   </issueManagement>
   <scm>
-    <connection>scm:git:https://git.eclipse.org/r/jdt/eclipse.jdt.core.git</connection>
+    <connection>scm:git:git://git.eclipse.org/gitroot/jdt/eclipse.jdt.core.git</connection>
     <url>https://git.eclipse.org/c/jdt/eclipse.jdt.core.git</url>
   </scm>
   <developers>
diff --git a/0001-Always-generate-bytecode-debuginfo.patch b/ecj-rpmdebuginfo.patch
similarity index 61%
rename from 0001-Always-generate-bytecode-debuginfo.patch
rename to ecj-rpmdebuginfo.patch
index 6bc2c92..e2727a1 100644
--- a/0001-Always-generate-bytecode-debuginfo.patch
+++ b/ecj-rpmdebuginfo.patch
@@ -1,18 +1,13 @@
-From e7ff390ef777bd818ccc6e6f8f3a56f36020abfe Mon Sep 17 00:00:00 2001
-From: Mat Booth <mat.booth@gmail.com>
-Date: Wed, 15 Sep 2021 10:21:53 +0100
-Subject: [PATCH 1/2] Always generate bytecode debuginfo
-
-When ecj is used to build RPMs
----
- .../jdt/internal/compiler/batch/Main.java     | 23 +++++++++++++++++++
- 1 file changed, 23 insertions(+)
-
-diff --git a/org/eclipse/jdt/internal/compiler/batch/Main.java b/org/eclipse/jdt/internal/compiler/batch/Main.java
-index f77372d..73a0d24 100644
---- a/org/eclipse/jdt/internal/compiler/batch/Main.java
-+++ b/org/eclipse/jdt/internal/compiler/batch/Main.java
-@@ -3109,6 +3109,29 @@ public void configure(String[] argv) {
+### Eclipse Workspace Patch 1.0
+#P org.eclipse.jdt.core
+Index: batch/org/eclipse/jdt/internal/compiler/batch/Main.java
+===================================================================
+RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/batch/org/eclipse/jdt/internal/compiler/batch/Main.java,v
+retrieving revision 1.327
+diff -u -r1.327 Main.java
+--- batch/org/eclipse/jdt/internal/compiler/batch/Main.java	21 Apr 2008 15:00:59 -0000	1.327
++++ batch/org/eclipse/jdt/internal/compiler/batch/Main.java	20 Nov 2008 19:26:57 -0000
+@@ -2609,6 +2609,29 @@
  		this.options.put(CompilerOptions.OPTION_Process_Annotations, CompilerOptions.ENABLED);
  	}
  
@@ -42,6 +37,3 @@ index f77372d..73a0d24 100644
  	this.logger.logCommandLineArguments(newCommandLineArgs);
  	this.logger.logOptions(this.options);
  
--- 
-2.31.1
-
diff --git a/ecj.spec b/ecj.spec
index e817455..b61626b 100644
--- a/ecj.spec
+++ b/ecj.spec
@@ -1,23 +1,24 @@
 Epoch:          1
 
-%global bundle_ver 3.29.0
+%global qualifier R-4.12-201906051800
 
 Name:           ecj
-Version:        4.23
+Version:        4.12
 Release:        1
 Summary:        the Eclipse Compiler for Java
 License:        EPL-2.0
 URL:            http://www.eclipse.org
 
-Source0:        https://download.eclipse.org/eclipse/downloads/drops4/R-%{version}-202203080310/ecjsrc-%{version}.jar
-Source1:        https://repo1.maven.org/maven2/org/eclipse/jdt/ecj/%{bundle_ver}/ecj-%{bundle_ver}.pom
+Source0:        http://download.eclipse.org/eclipse/downloads/drops4/%{qualifier}/ecjsrc-%{version}.jar
+Source1:        https://repo1.maven.org/maven2/org/eclipse/jdt/ecj/3.18.0/ecj-3.18.0.pom
 Source2:        MANIFEST.MF
+Source3:        java10api.jar
 
-Patch0:         0001-Always-generate-bytecode-debuginfo.patch
+Patch0: %{name}-rpmdebuginfo.patch
+Patch1: javaAPI.patch
 
 BuildArch:      noarch
 BuildRequires:  ant javapackages-local
-BuildRequires:  java-11-openjdk-devel
 
 %description
 ECJ is the the Eclipse Compiler for Java.  It is also known as the JDT Core batch compiler.
@@ -27,18 +28,21 @@ ECJ is the the Eclipse Compiler for Java.  It is also known as the JDT Core batc
 %prep
 %autosetup -c -n %{name}-%{version} -p1
 
-sed -i -e "s/Xlint:none/Xlint:none -encoding cp1252/g" build.xml
-rm -f org/eclipse/jdt/core/JDTCompilerAdapter.java
+sed -i -e 's|debuglevel=\"lines,source\"|debug=\"yes\"|g' build.xml
+
 cp %{SOURCE1} pom.xml
 mkdir -p scripts/binary/META-INF/
 cp %{SOURCE2} scripts/binary/META-INF/MANIFEST.MF
 
+rm -f org/eclipse/jdt/core/JDTCompilerAdapter.java
+
 %mvn_alias org.eclipse.jdt:ecj org.eclipse.jdt:core org.eclipse.jdt.core.compiler:ecj \
   org.eclipse.tycho:org.eclipse.jdt.core org.eclipse.tycho:org.eclipse.jdt.compiler.apt
+%mvn_artifact "org.eclipse:java10api:jar:10" %{SOURCE3}
+%mvn_alias "org.eclipse:java10api:jar:10" "org.eclipse:java9api:jar:9"
 
 %build
-export JAVA_HOME=/usr/lib/jvm/java-11
-ant
+ant -Djavaapi=%{SOURCE3}
 
 %install
 %mvn_artifact pom.xml ecj.jar
@@ -58,6 +62,9 @@ install -m 644 -p ecj.1 %{buildroot}%{_mandir}/man1/ecj.1
 %{_mandir}/man1/ecj*
 
 %changelog
+* Mon May 23 2022 chenchen <chen_aka_jan@163.com> - 1:4.12-1
+- downgrade to 4.12
+
 * Wed May 18 2022 chenchen <chen_aka_jan@163.com> -  1:4.23-1
 - update to 4.23
 
diff --git a/ecjsrc-4.12.jar b/ecjsrc-4.12.jar
new file mode 100644
index 0000000..eacd58a
Binary files /dev/null and b/ecjsrc-4.12.jar differ
diff --git a/ecjsrc-4.23.jar b/ecjsrc-4.23.jar
deleted file mode 100644
index 9b0a8be..0000000
Binary files a/ecjsrc-4.23.jar and /dev/null differ
diff --git a/java10api.jar b/java10api.jar
new file mode 100644
index 0000000..464b691
Binary files /dev/null and b/java10api.jar differ
diff --git a/javaAPI.patch b/javaAPI.patch
new file mode 100644
index 0000000..cd8d1b5
--- /dev/null
+++ b/javaAPI.patch
@@ -0,0 +1,26 @@
+--- a/build.xml.orig	2018-03-20 15:15:57.063810672 +0000
++++ b/build.xml	2018-03-20 15:16:26.018700633 +0000
+@@ -15,16 +15,20 @@
+ 	<property name="output" value="bin" />
+ 	<property name="jar_file" value="ecj.jar" />
+ 
++	<path id="build.path">
++		<pathelement path="${javaapi}"/>
++		<pathelement path="/usr/lib/jvm/java-1.8.0/jre/lib/rt.jar"/>
++	</path>
+ 	<target name="build">
+ 		<delete file="${basedir}/${jar_file}" failonerror="no" />
+ 		<delete dir="${output}" failonerror="no" />
+ 		<mkdir dir="${output}" />
+ 
+-		<javac srcdir="${basedir}" destdir="${output}"
+-					debuglevel="lines,source"
++		<javac srcdir="${basedir}" destdir="${output}" bootclasspathref="build.path"
++					debug="yes"
+ 					source="1.8"
+ 					target="1.8">
+-			<compilerarg line="-Xlint:none"/>
++			<compilerarg line="-Xlint:none -encoding cp1252"/>
+ 		</javac>
+ 
+ 		<delete file="${basedir}/META-INF/MANIFEST.MF" failonerror="false"/>