Error: function 'execLaterFdNative' not provided by package 'later'

[jcheng5]

NOTICE: If you're seeing this error, install.packages("later") and restarting R should fix it. If not, please leave a comment including packageVersion("later")

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This error is happening when a copy of a LinkingTo: later package (like httpuv or promises) is installed that was built against later 1.4.0, but the version of later that's actually installed is 1.3.1 or earlier.

This is not academic; it happens for many deployed Shiny apps if they are installing binary packages from CRAN or Posit Package Manager.

For example:

1. Last week you took a snapshot of your app to create a manifest.json which contains package names and version numbers. Among the entries are httpuv 1.6.15 and later 1.3.1. All is well.
2. Now you've updated your app logic so you redeploy. The container or whatever is rebuilt. The manifest.json hasn't changed, so httpuv 1.6.15 and later 1.3.1 are installed. But now, httpuv 1.6.15 has been rebuilt against the newest later.
3. When httpuv goes to load, you get the above error; the inst/include/later.h is trying to load an RCCallable that doesn't exist.

[jcheng5]

Easy local repro steps (using promises instead of httpuv as it's much faster to compile):

install.packages("later")
install.packages("promises", type="source")
devtools::install_version("later", "1.3.1")

Then restart R and library(promises).

[jcheng5]

#204 takes the approach of looking at later's runtime API version number (kudos to @wch for adding that five years ago!).

Another option would be to leave the version number and call R_GetCCallable with error handlers. We could then reserve version number incrementing for true backwards-compatible breaking changes and simply error if there's a version mismatch.

@shikokuchuo I know it's getting late there but I'd really like to get this fixed today--do you have a moment for a quick zoom call? I can do the work but would like to have your approval on the approach.

[shikokuchuo]

@jcheng5 I've messaged you on Slack.