Tycho cannot download from official p2 repository - eclipse-rcp

Question

I have a Eclipse E4 application that is already build by Tycho. Now we are migrating the application to use Java 12. Herefore we also need to update our target file.
The latest target file looks like:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?pde version="3.8"?>
<target includeMode="feature" name="Running Platform">
<locations>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="http://download.eclipse.org/nattable/releases/1.5.0/repository/"/>
<unit id="org.eclipse.nebula.widgets.nattable.core.feature.feature.group" version="1.5.0.201703192131"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.e4.feature.feature.group" version="1.1.0.201703192131"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.glazedlists.feature.feature.group" version="1.5.0.201703192131"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.nebula.feature.feature.group" version="1.1.0.201703192131"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.poi.feature.feature.group" version="1.5.0.201703192131"/>
</location>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="http://download.eclipse.org/releases/2019-06/"/>
<unit id="org.eclipse.equinox.sdk.feature.group" version="3.18.0.v20190528-1257"/>
<unit id="org.eclipse.platform.sdk" version="4.12.0.I20190605-1800"/>
</location>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="http://download.eclipse.org/nebula/releases/latest"/>
<unit id="org.eclipse.nebula.widgets.pshelf.css.feature.feature.group" version="1.0.0.201812241324"/>
<unit id="org.eclipse.nebula.widgets.pshelf.feature.feature.group" version="1.0.0.201812241324"/>
</location>
</locations>
<environment>
<arch>x86_64</arch>
<os>win32</os>
<ws>win32</ws>
<nl>en_US</nl>
</environment>
</target>
When we run the build with tycho using Jenkins we are getting following error:
[INFO] Fetching p2.index from http://download.eclipse.org/nattable/releases/1.5.0/repository/
[INFO] Fetching p2.index from http://download.eclipse.org/nattable/releases/1.5.0/repository/
[INFO] Adding repository http://download.eclipse.org/nattable/releases/1.5.0/repository
[INFO] Fetching p2.index from http://download.eclipse.org/releases/2019-06/
[INFO] Fetching p2.index from http://download.eclipse.org/releases/2019-06/
[INFO] Adding repository http://download.eclipse.org/releases/2019-06
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.eclipse.ecf.provider.filetransfer.httpclient4.SNIAwareHttpClient$1 (file:/C:/Users/PTITDevTools_svc/.m2/repository/org/eclipse/tycho/tycho-bundles-external/1.1.0/eclipse/plugins/org.eclipse.ecf.provider.filetransfer.httpclient4_1.1.200.v20170314-0133.jar) to method sun.security.ssl.SSLSocketImpl.setHost(java.lang.String)
WARNING: Please consider reporting this to the maintainers of org.eclipse.ecf.provider.filetransfer.httpclient4.SNIAwareHttpClient$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
[ERROR] Failed to resolve target definition D:\Software\x64\Jenkins\workspace\ture_ILMV-490-migrate-to-java-12\neon\neon.target: Failed to load p2 metadata repository from location http://download.eclipse.org/releases/2019-06/: Unable to read repository at http://download.eclipse.org/releases/2019-06. Unable to read repository at https://download.eclipse.org/technology/epp/packages/2019-06/content.xml. Connection reset -> [Help 1]
With our old Target file the build was working but the old file was a PDE target file. Can someone tell me why this is failing?

Answer 1

The url of the Eclipse p2 repo was not specific enough.
I changed http://download.eclipse.org/releases/2019-06/ to http://download.eclipse.org/releases/2019-06/201906191000