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running examples with enhanced help engine also requires mime package

3 messages · Kevin Ushey, Duncan Murdoch, Deepayan Sarkar

Original
Kevin Ushey
# 
Hi,

The new enhanced help system is fantastic! I've been playing around
with the enhanced help system introduced recently in R 4.2.0, and I
noticed one minor issue. When attempting to run examples from within a
Help page (in HTML help), if the knitr package is not installed, one
sees:

    To view output in the browser, the knitr package must be installed.

I think this is expected. However, after installing the 'knitr'
package and attempting to run examples again, I see:

    Error in loadNamespace(x) : there is no package called 'mime'

as it looks like 'knitr' (or a dependency?) is trying to use 'mime'
behind the scenes in the Help server. Because 'mime' is not an
explicit dependency of 'knitr', running install.packages("knitr")
isn't sufficient to ensure 'mime' is also installed (which a user
might have expected).

I'm not sure if this should be resolved in 'knitr' (e.g. via just
depending on the 'mime' package) or if this should be tweaked in R
itself.

Thanks,
Kevin
Duncan Murdoch
#
On 25/03/2022 12:07 p.m., Kevin Ushey wrote:
This is related:

    https://github.com/yihui/xfun/issues/63

Duncan Murdoch
1 day later
Deepayan Sarkar
#
On Fri, Mar 25, 2022 at 9:48 PM Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
Thanks for the report and diagnosis.

I guess the R-level workaround would be to write a replacement for
knitr::image_uri(). That would probably have been fine if we forced
png to be the only output format, but I see no reason to restrict to
specific formats, so the flexibility is useful.

So I'll just add mime to the message.

Best,
-Deepayan