Potential solution to INS-32715 when executing runInstaller

Error when running runInstaller:

[FATAL] [INS-32715] The source home (/u01/oracle/product/19c) is not registered in the central inventory.
   ACTION: Ensure that the source home is registered in the central inventory.

Cause:
There is something wrong with the inventory, although it seems correct.

Find the inventory file:

opatch lsinventory

Oracle Home       : /u01/oracle/product/19c
Central Inventory : /u01/oraInventory
   from           : /u01/oracle/product/19c/oraInst.loc

Check the file for obvious errors:

cd /u01/oraInventory/ContentsXML
cat inventory.xml (excerpt)

<HOME_LIST>
<HOME NAME="19c" LOC="/u01/oracle/product/19c" TYPE="O" IDX="8"/>
</HOME_LIST>

Solution:

Attach the ORACLE_HOME to the inventory once more, even though it looks correct to begin with:
 $ORACLE_HOME/oui/bin/runInstaller -silent -attachHome ORACLE_HOME="$ORACLE_HOME" ORACLE_HOME_NAME="19c"
Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB.   Actual 25599 MB    Passed
The inventory pointer is located at /etc/oraInst.loc
You can find the log of this install session at:
 /home/oracle/oraInventory/logs/AttachHome2025-02-06_01-07-51PM.log
'AttachHome' was successful.

Try the runInstaller command again, and it should work.