Hey guys how i can fix this error?
Java JDK Installed: Java SE Development Kit 15.0.1

Error log:
== MCP 9.18 (data: 9.18, client: 1.8.8, server: 1.8.8) ==
"scalac" is not found on the PATH. Scala files will not be recompiled
# found ff, ff patches, srgs, name csvs, doc csvs, param csvs, astyle, astyle config, rg, ss
Looking in C:\Users\bird\AppData\Roaming\.minecraft\versions for mc installs... OK
Copying assets... OK
Parsing JSON file... OK
Looking for minecraft main jar... Not found
Copying minecraft main jar... OK
> Checking libraries...
Copying library jinput... OK
Copying library lwjgl-platform... OK
Copying library icu4j-core-mojang... OK
Copying library twitch-external-platform... OK
Copying library httpcore... OK
Copying library log4j-api... OK
Copying library commons-lang3... OK
Copying library jna... OK
Copying library libraryjavasound... OK
Copying library jopt-simple... OK
Copying library guava... OK
Copying library oshi-core... OK
Copying library httpclient... OK
Copying library commons-compress... OK
Copying library platform... OK
Copying library codecjorbis... OK
Copying library soundsystem... OK
Copying library librarylwjglopenal... OK
Copying library lwjgl_util... OK
Copying library commons-codec... OK
Copying library jutils... OK
Copying library commons-logging... OK
Copying library lwjgl... OK
Copying library commons-io... OK
Copying library realms... OK
Copying library authlib... OK
Copying library gson... OK
Copying library netty... OK
Copying library twitch... OK
Copying library codecwav... OK
Copying library twitch-platform... OK
Copying library jinput-platform... OK
Copying library log4j-core... OK
Copying library netty-all... OK
> Checking Natives...
Extracting native avutil-ttv-51.dll... OK
Extracting native lwjgl.dll... OK
Extracting native OpenAL32.dll... OK
Extracting native jinput-dx8_64.dll... OK
Extracting native libmfxsw64.dll... OK
Extracting native jinput-wintab.dll... OK
Extracting native twitchsdk.dll... OK
Extracting native jinput-dx8.dll... OK
Extracting native libmp3lame-ttv.dll... OK
Extracting native jinput-raw.dll... OK
Extracting native OpenAL64.dll... OK
Extracting native jinput-raw_64.dll... OK
Extracting native swresample-ttv-0.dll... OK
Extracting native lwjgl64.dll... OK
== Decompiling client using fernflower ==
> Creating SRGs
> Applying SpecialSource
> Applying MCInjector
> Creating renamed srg
> Filtering classes
> Decompiling
> Unpacking jar
> Copying sources
> Applying fernflower fixes
> Applying patches
'runtime\bin\applydiff.exe -p1 -u -i ..\..\temp\temp.patch -d src\minecraft' failed : 1

== ERRORS FOUND ==

1 out of 1 hunk FAILED -- saving rejects to file 'net\minecraft\util\Cartesian.jav#'
==================

> Cleaning comments
- Done in 108.28 seconds
== Reformating client ==
> Cleaning sources
> Replacing OpenGL constants
> Reformating sources
- Done in 23.23 seconds
== Updating client ==
> Adding javadoc
> Renaming sources
- Done in 24.91 seconds
!! Missing server jar file. Aborting !!
== Recompiling client ==
> Cleaning bin
> Recompiling
'"javac" -Xlint:-options -deprecation -g -source 1.6 -target 1.6 -classpath "jars\versions\1.8.8\1.8.8.jar;lib;lib\*;jars\libr aries\net\java\jinput\jinput\2.0.5\jinput-2.0.5.jar;jars\libraries\org\lwjgl\lwjgl\lwjgl-platform\2.9.4-nightly-20150209\lwjgl-platform-2.9.4-nightly-20150209-natives-windows.jar;jars\libraries\com\ibm\icu\icu4j-core-mojang\51.2\icu4j-core-mojang-51.2.jar;jars\libraries\tv\twitch\twitch-external-platform\4.5\twitch-external-platform-4.5-natives-windows-64.jar;jars\libraries\org\apache\httpcomponents\ht tpcore\4.3.2\httpcore-4.3.2.jar;jars\libraries\org\apache\logging\log4j\ log4j-api\2.0-beta9\log4j-api-2.0-beta9.jar;jars\libraries\org\apache\commons\common s-lang3\3.3.2\commons-lang3-3.3.2.jar;jars\libraries\net\java\dev\jna\jna\3.4. 0\jna-3.4.0.jar;jars\libraries\com\paulscode\libraryjava sound\20101123\libraryjavasound-20101123.jar;jars\libraries\net\sf\jopt-simple\jopt-simple\4.6\jopt-simple-4.6.jar;jars\libraries\com\google\guava\guava\17.0 \guava-17.0.jar;jars\libraries\oshi-project\oshi-core\1.1\oshi-core-1.1.jar;jars\libraries\org\apache\httpcomponents\h ttpclient\4.3.3\httpclient-4.3.3.jar;jars\libraries\org\apache\commons\common s-compress\1.8.1\commons-compress-1.8.1.jar;jars\libraries\net\java\dev\jna\platform \3.4.0\platform-3.4.0.jar;jars\libraries\com\paulscode\codecjorbis \20101023\codecjorbis-20101023.jar;jars\libraries\com\paulscode\soundsys tem\20120107\soundsystem-20120107.jar;jars\libraries\com\paulscode\libraryl wjglopenal\20100824\librarylwjglopenal-20100824.jar;jars\libraries\org\lwjgl\lwjgl\lwjgl_ util\2.9.4-nightly-20150209\lwjgl_util-2.9.4-nightly-20150209.jar;jars\libraries\commons-codec\commons-codec\1.9\commons-codec-1.9.jar;jars\libraries\net\java\jutils\jutils\1.0. 0\jutils-1.0.0.jar;jars\libraries\commons-logging\commons-logging\1.1.3\commons-logging-1.1.3.jar;jars\libraries\org\lwjgl\lwjgl\lwjgl\2.9 .4-nightly-20150209\lwjgl-2.9.4-nightly-20150209.jar;jars\libraries\commons-io\commons-io\2.4\commons-io-2.4.jar;jars\libraries\com\mojang\realms\1.7.39\re alms-1.7.39.jar;jars\libraries\com\mojang\authlib\1.5.2 1\authlib-1.5.21.jar;jars\libraries\com\google\code\gson\gso n\2.2.4\gson-2.2.4.jar;jars\libraries\com\mojang\netty\1.6\nett y-1.6.jar;jars\libraries\tv\twitch\twitch\6.5\twitch-6.5.jar;jars\libraries\com\paulscode\codecwav\2010 1023\codecwav-20101023.jar;jars\libraries\tv\twitch\twitch-platform\6.5\twitch-platform-6.5-natives-windows-64.jar;jars\libraries\net\java\jinput\jinput-platform\2.0.5\jinput-platform-2.0.5-natives-windows.jar;jars\libraries\org\apache\logging\log4 j\log4j-core\2.0-beta9\log4j-core-2.0-beta9.jar;jars\libraries\io\netty\netty-all\4.0.23.Final\netty-all-4.0.23.Final.jar" -sourcepath src\minecraft -d bin\minecraft @Temp\java_src_client.txt' failed : 2

== ERRORS FOUND in JAVA CODE ==

error: Source option 6 is no longer supported. Use 7 or later.
error: Target option 6 is no longer supported. Use 7 or later.
==================

Initial client recompile failed, correct source then run updatemd5
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