flex: problem with installation mxml compiler on Mac OS Catalina

I am reading a book Bruce Eckel "Thinking in java". For Flex chapter I am trying to instal mxml-compiler. While I'm doing it some problems appear. What I have done: I installed Air sdk because I read that its peccary to do for working with mxml compiler, after that I installed apache-flex-sdk-installer because I found out that it is the simpliest way to install a compiler. Finally for building the installer I downloaded ant and did the next: In the ant_on_air directory of apache-flex-sdk-installer folder I run: ant -DFLEX_HOME=/path/to/apache/flex/sdk -DAIR_HOME=/path/to/air/sdk And get the next error: compile:

BUILD FAILED /Users/pavel1709/Desktop/apache-flex-sdk-installer-3.3.2-src/ant_on_air/build.xml:139: Problem: failed to create task or type compc Cause: The name is undefined. Action: Check the spelling. Action: Check that any custom tasks/types have been declared. Action: Check that any / declarations have taken place.

If we get into /Users/pavel1709/Desktop/apache-flex-sdk-installer-3.3.2-src/ant_on_air/build.xml we will see:

   <target name="compile" 
        description="Compiles the SWC.">
        <compc 
            output="${LIBRARY_DIR}/${LIBRARY_NAME}.swc"
            swf-version="23"
            debug="${DEBUG_FLAG}"
            failonerror="true"
            fork="true"
            maxmemory="512m">
            <source-path path-element="${SOURCE_DIR}"/>
            <source-path path-element="${basedir}/locale/{locale}"/>
            <source-path path-element="${basedir}/external"/>
            <load-config filename="${FLEX_HOME}/frameworks/air-config.xml"/>
            <external-library-path file="${AIR_HOME}/frameworks/libs/air/airglobal.swc" append="true"/>
            <external-library-path file="${basedir}/external/libs" append="true"/>
            <include-classes>AntClasses</include-classes>

        </compc>
    </target>

139 line is maxmemory="512m", but I'm pretty sure the problem isn't in it. I will be glad if you help me to solve this problem. Thanks!