issue with non-writable available package index

[hutch3232]

Main issue:

renv::install("pkgname") hangs indefinitely on renv >= 0.17.0 due to my non-standard setup.

Details:

I have a large renv cache being used by many people. It's defined using the RENV_PATHS_ROOT environmental variable. That location is read-only* (for most users). For renv prior to 0.17.0 that would result in successful installs (simply a symlink) if the package existed in the cache and an error if it did not (because it can't write there).

Now, however, it seems to hang due to renv:::available_packages.

I found that if I run options(renv.index.enabled=FALSE) the old behavior is restored.

I'm wondering if there could be a solution where the index will automatically be used if it can succeed (maybe just a file.access test or something for write-ability) and disabled otherwise? Essentially to avoid having to specify this option in every project.

I realize this is probably a very uncommon setup so understand if this isn't worth it.

* The reason my setup is like this is because we have the renv cache mounted to Docker environments and for technical reasons the mounts need to be read-only. There is a separate process (where the cache is writable) to add new packages.

Thanks for the awesome package!

[kevinushey]

Thanks for the bug report! I want renv to work out-of-the-box in cases like yours as well so I'd like to consider if there's a better way for renv to handle this.

As a workaround, you could place the available packages index in a shared location, with something like:

RENV_PATHS_INDEX = <path/to/shared/writable/location>

And that could be added to your R installation's etc/Rprofile.site so it would be active for all R installations.

[kevinushey]

Perhaps the index could be placed in a location like this by default:

<renvRoot>/shared/<index>

And system administrators could allow that directory to be considered readable + writable by all users by default if desired?

[hutch3232]

Thanks for these ideas! I tested the option of setting RENV_PATHS_INDEX to my /.../R proj/renv/index, where index is a new folder, and that worked well. I like this approach because it's presumably always going to be writeable. I'm guessing it's not the default because then others aren't getting to refer to it (even in cases where RENV_PATHS_ROOT is writeable. Setting the etc/Rprofile.site is a good idea too and might work for me.

[hutch3232]

I haven't had a chance yet to test your fix yet 998c043 but I was also looking at my renv setup in a different environment where it is shared between many users and is also writeable (due to using RENV_CACHE_MODE) and I noticed the cached available packages .rds files are accumulating. I think the intent was to remove the old one when creating a new one, but in my case since someone else wrote the .rds file, I'm unable to remove it.

renv/R/index.R

Line 187 in e24dfb3

unlink(file.path(root, entry$data))

I wonder if the RENV_CACHE_MODE could be used to set the mode of the created .rds in a way similar to the tarballs under source/ and the packages under cache/.

[kevinushey]

Thanks for the heads up -- I'll take a look at that.

[kevinushey]

I think these commits should help:

9abe0db
1178600

Let me know if those make a difference.

[kevinushey]

(I think it should be okay to make these index files shared by default, rather than checking RENV_CACHE_MODE, but let me know if you disagree)

[hutch3232]

Finally had a chance to test out these commits. Thank you for making these changes! It seems like this will work well and I like the approach taken.

[kevinushey]

Great to hear -- thank you!