How to clear/delete a cache variable

Question

Trying to get `find_path` to do what I want. ``` find_path(temmp include/help.h) message("temmp= ${temmp}") ``` help.h is found. The output is `temmp= /usr/local/toolA` ``` find_path(temmp include/foo.shoe) message("temmp= ${temmp}") ``` foo.shoe does not exist (not found). The output is `temmp= /usr/local/toolA` The cache variable exists, so the variable (temmp) is untouched. I try and clear the cache var with this: ``` set (temmp "" CACHE INTERNAL "") find_path(temmp include/help.h) message("temmp= ${temmp}") ``` No change. The variable is cleared, but still exists. The output is `temmp=` (`find_path` does not run.) How can I delete the `temmp` variable from the cache? (I want to force the `find_path` to run again.)

Accepted Answer

You can use `unset`:

```
unset(temmp CACHE)
```

As an aside, the `find_path` calls should be more like:

```
find_path(temmp help.h include)
```

How to clear/delete a cache variable

Solution

Problem