A collection of general tips to assist developers to conduct troubleshooting. Some FOLIO repositories also have specific notes.

Keep system tools up-to-date

As explained in the FOLIO setup documentation, keeping the operating system and tools up-to-date will generally help to avoid issues.

Missing certificate authority for Let’s Encrypt

If you are using a version of the Oracle JDK prior to 1.8.0_101 then the Let’s Encrypt certificate authority is not in the Java trust store (see notes). So it will not be possible to download components from the FOLIO Maven repository. You will see error messages like:

Could not resolve dependencies for project org.folio:mod-users:jar:0.1-SNAPSHOT: Failed to collect dependencies at org.folio:domain-models-api-interfaces:jar:0.0.1-SNAPSHOT: Failed to read artifact descriptor for org.folio:domain-models-api-interfaces:jar:0.0.1-SNAPSHOT: Could not transfer artifact org.folio:domain-models-api-interfaces:pom:0.0.1-SNAPSHOT from/to folio-nexus (https://repository.folio.org/repository/maven-folio): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target -> [Help 1]

The fix is just to replace your JDK with a sufficiently recent replacement. (Or you can use OpenJDK, which has supported Let’s Encrypt for longer.)

Update git submodules

Some FOLIO repositories utilize “git submodules” for sections of common code. Some git clients do not handle this properly. See notes.

Other troubleshooting documents