Ant <get>: Download of Ivy.jar suddenly results in PKIX error - ant

Question

The download of the Apache Ivy jar inside my Ant script worked for years. Suddenly a SSLHandshakeException occurs. Why is that?
Ant script snippet:
<target name="download-ivy" unless="offline">
<mkdir dir="${ivy.jar.dir}"/>
<!-- download Ivy from web site so that it can be used even without any special installation -->
<get src="https://repo1.maven.org/maven2/org/apache/ivy/ivy/2.5.0/ivy-2.5.0.jar"
dest="${ivy.jar.file}" usetimestamp="true" verbose="true" retries="10"/>
</target>
Console output:
download-ivy:
[get] Getting: https://repo1.maven.org/maven2/org/apache/ivy/ivy/2.5.0/ivy-2.5.0.jar
[get] To: C:\Users\mp\.ant\lib\ivy.jar
[get] local file date : Sun Oct 20 12:39:20 CEST 2019
[get] Error getting https://repo1.maven.org/maven2/org/apache/ivy/ivy/2.5.0/ivy-2.5.0.jar to C:\Users\mp\.ant\lib\ivy.jar
BUILD FAILED
ivytargets.xml:18: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1946)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:316)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:310)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1639)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1395)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1379)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:162)
at org.apache.tools.ant.taskdefs.Get$GetThread.openConnection(Get.java:731)
at org.apache.tools.ant.taskdefs.Get$GetThread.get(Get.java:652)
at org.apache.tools.ant.taskdefs.Get$GetThread.run(Get.java:642)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:302)
at sun.security.validator.Validator.validate(Validator.java:262)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1621)
... 13 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
... 19 more

Answer 1

The SSLHandshakeException is apparently related to the specific JDK 8 version (jdk8u192-b12) used in this case.
Using another JDK version (jdk-8.0.322.6-hotspot) does not report any problem and succeeds in downloading the Ivy jar.