--- re-building 'foto-background.Rmd' using rmarkdown

processing vignette 'foto-background.Rmd' failed with diagnostics:

Vignette re-building failed.

Build process failed

Process completed with exit code 1.

The vignette title specified in \VignetteIndexEntry{} is different from the title in the YAML metadata. The former is "foto functionality", and the latter is "foto". If that is intentional, you may set options(rmarkdown.html_vignette.check_title = FALSE) to suppress this check.