Hi Scott,
Sorry for dusting off this old topic, but I've got a similar problem. We've got a pretty complex structure for our unlocked package and I've tried to do configuration as you've described, however, every single time I'm trying to save any apex class I get an error "Deployment Complete Deployed 0/41 components to FridayUnlockedTest in 1 s 377 ms with status FAILED."
Projects' .iml file looks as follows:
<?xml version="1.0" encoding="UTF-8"?>
<module type="IlluminatedCloud" version="4">
<component name="FacetManager">
<facet type="IlluminatedCloud" name="Illuminated Cloud">
<configuration>
<option name="connectionName" value="FridayUnlockedTest" />
<option name="connectionType" value="OAUTH" />
<option name="defaultSourceRootUrl" value="file://$MODULE_DIR$/force-app" />
<option name="moduleContents">
<ModuleContents>
<option name="contentSelectionType" value="PACKAGE_XML" />
<option name="packageXmlRelativePath" value="manifest/package.xml" />
</ModuleContents>
</option>
</configuration>
</facet>
</component>
<component name="NewModuleRootManager" inherit-compiler-output="true">
<exclude-output />
<content url="file://$MODULE_DIR$">
<sourceFolder url="file://$MODULE_DIR$/force-app" type="java-resource" />
<sourceFolder url="file://$MODULE_DIR$/force-app/commons/core" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/commons/selectorLayer" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/commons/triggerHandler" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/default" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/domain" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/selectors" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/services" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/triggerHandlers" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/main/utils" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/manageResources" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/manageTimesheets" isTestSource="false" />
<sourceFolder url="file://$MODULE_DIR$/force-app/timesheetApprovals" isTestSource="false" />
</content>
<orderEntry type="jdk" jdkName="IlluminatedCloud (friday/FridayUnlockedTest)" jdkType="IlluminatedCloud" />
<orderEntry type="sourceFolder" forTests="false" />
</component>
</module>
As you can see, we've got plenty of folders marked as Source, however, this doesn't work (except for LWC, Objects, Layouts and a few other - those components seem to save without any problems). Below is a sample screenshot of what the folders look like:
Any help would be much appreciated :)
Best regards,
Paweł Iwanowicz.