Hello,

while working on another thing, I noticed that when use_bootstrap_container project option was introduced (Wed Jun 14 this year), it was introduced as enabled for existing COPR projects at that time. That was not exactly intended as this feature is experimental.

Enabling this option makes mock setup two chroots during build:

- "bootstrap" one with the latest dnf, rpm (and other build tools) for the given build chroot (e.g. fedora-26-x86_64)
- the one where the build is actually run (which is of the same os, version, and arch as the bootstrap one) and that is initially setup by the tools from the bootstrap one

This makes build last a bit longer (in order of minutes depending on package download speed) and it might cause a build to fail unexpectedly in case there is e.g. bug in rawhide dnf (or in experimental dnf that is built in your copr chroot).

If this option is disabled, host (builder) system dnf is used to setup the build chroot. There is no bootstrap chroot setup and hence it is faster.

The longer running time might be a problem so, please, if you are a long term users of COPR and you don't want the feature enabled, check your project settings and disable it.

Sorry for accidentally enabling it
clime