Hi, While analyzing a Yocto bug[0] I think I've identified a problem in kconfig. The problem happens if you have a hex or int type config without a default value. Like this : config TEST_KCONFIG hex "Test kconfig" # No default value ... and try to start oldconfig with a closed stdin (like we have in Yocto): echo -n "" | make oldconfig When this happens, oldconfig prompts for the value of TEST_KCONFIG but stdin is closed it get the global default value : an empty string. This is not a valid hex/int value so it prompts again, hence the infinite loop. I'm having trouble pointing where the bug is exactly : * Should the global default value for hex/int be valid in their context? (like the minimal value of the range or 0/0x0) * Must all int/hex config provide a valid default value? (This is the case for hex config in the kernel). This would have to be documented somewhere (Some other KConfig implementation did [1]) * Should all oldconfig/syncconfig/... exit with an error when trying to prompt on a closed stdin? (I might be able to send a patch for this one) NB: I know of olddefconfig but in the case of U-boot, syncconfig is used at a later stage and the problem appears again. What do you think? Regards, [0]: https://bugzilla.yoctoproject.org/show_bug.cgi?id=14136 [1]: https://docs.zephyrproject.org/1.14.0/guides/kconfig/index.html#redundant-defaults -- Yoann Congal Smile ECS - Tech Expert
