create-temporary-file and create-temporary-directory are subject to race conditions

[Mario Domenech Goulart]

Both use the non-atomic strategy of checking if a file system object exists then act, which may lead to race conditions.

create-temporary-directory is specially more fragile because it uses directory-exists? to check if a file system object exists. So, for example, if a regular file with the same name as the attempted one exists, create-temporary-directory will fail.

[felix winkelmann]

What would be a suitable approach to make this work?

[Vasilij Schneidermann]

The recommended approach is to remove the check bit and instead handle any error happening during file/directory creation. While it's uglier, it avoids the race condition.