Cryptic error from install_github() if reference doesn't exist

[jennybc]

If you try to install from github ref that doesn't exist, the error message can be pretty odd. Here's an attempt to install from a PR that has been closed and the underlying branch deleted.

devtools::install_github("rstudio/rmarkdown#711")
#> Using GitHub PAT from envvar GITHUB_PAT
#> Using GitHub PAT from envvar GITHUB_PAT
#> Downloading GitHub repo rstudio/rmarkdown@feature/html-vignette-readme
#> from URL https://api.github.com/repos/rstudio/rmarkdown/zipball/feature/html-vignette-readme
#> No encoding supplied: defaulting to UTF-8.
#> Error: lexical error: invalid char in json text.
#>                                        Not Found
#>                      (right here) ------^

I get same message for a tag or SHA or branch that never existed, i.e., devtools::install_github("rstudio/rmarkdown@v5") or devtools::install_github("rstudio/rmarkdown@1234567") of devtools::install_github("rstudio/rmarkdown@nope").

But the error for a PR that never existed is different and is more informative.

devtools::install_github("rstudio/rmarkdown#20000")
#> Using GitHub PAT from envvar GITHUB_PAT
#> condition in stop(github_error(req)): Not Found (404)
#> *

[jimhester]

GitHub returns a regular HTTP response in the first case, whereas in the second it returns a JSON response. Devtools is always expecting a JSON response, which is why you got the confusing error.

#1211 tries to parse the response as JSON, if it fails it treats the response content as a message which cleans up this issue.

download_github(tempfile(), "https://api.github.com/repos/rstudio/rmarkdown/zipball/feature/html-vignette-readme")
#> Error in stop(github_error(request)) : Not Found (404)

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/