Once in dnf.base.Base._setup_default_conf() and once in dnf.cli.cli.Cli._configure_cachedir(). This was broken in 9b6de97c71f5b32929e9f23bd1dc7c6cb33dd67d. I think CACHEDIR_SUFFIX should be appended to cachedir only once after releasever and possibly arch (bug 1190854) have been set.
*** Bug 1195432 has been marked as a duplicate of this bug. ***
*** Bug 1195956 has been marked as a duplicate of this bug. ***
*** Bug 1197547 has been marked as a duplicate of this bug. ***
hawkey-0.5.4-1.fc22,dnf-0.6.5-1.fc22 has been submitted as an update for Fedora 22. https://admin.fedoraproject.org/updates/hawkey-0.5.4-1.fc22,dnf-0.6.5-1.fc22
Package hawkey-0.5.4-1.fc22, dnf-0.6.5-1.fc22: * should fix your issue, * was pushed to the Fedora 22 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing hawkey-0.5.4-1.fc22 dnf-0.6.5-1.fc22' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2015-5337/hawkey-0.5.4-1.fc22,dnf-0.6.5-1.fc22 then log in and leave karma (feedback).
dnf-plugins-extras-0.0.6-2.fc22,yum-utils-1.1.31-505.fc22,yum-3.4.3-505.fc22,hawkey-0.5.4-1.fc22,dnf-0.6.5-1.fc22 has been submitted as an update for Fedora 22. https://admin.fedoraproject.org/updates/dnf-plugins-extras-0.0.6-2.fc22,yum-utils-1.1.31-505.fc22,yum-3.4.3-505.fc22,hawkey-0.5.4-1.fc22,dnf-0.6.5-1.fc22
dnf-plugins-extras-0.0.6-2.fc22, yum-3.4.3-505.fc22, dnf-0.6.5-1.fc22, yum-utils-1.1.31-505.fc22, hawkey-0.5.4-1.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
dnf-plugins-core-0.1.5-2.fc21,dnf-0.6.4-5.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/dnf-plugins-core-0.1.5-2.fc21,dnf-0.6.4-5.fc21
dnf-plugins-core-0.1.5-2.fc21, dnf-0.6.4-5.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.