When Bioconductor packages are first accepted into the project, unlike CRAN, they only appear in the Development branch until the next release of R, when the Development branch becomes the Release branch and a new Development branch is created. The installer won't install the package into the stable version of R. This means that a newly accepted Bioconductor package can't be installed into RStudio Cloud for up to a few months.
> library(BiocManager)
> install("DelayedDataFrame")
Warning message:
package ‘DelayedDataFrame’ is not available (for R version 3.5.2)
It's a success in R Under Development.
> install("DelayedDataFrame")
Bioconductor version 3.9 (BiocManager 1.30.4), R Under development (unstable) (2019-02-22 r76149)
Installing package(s) 'DelayedDataFrame'
trying URL 'https://bioconductor.org/packages/3.9/bioc/bin/windows/contrib/3.6/DelayedDataFrame_0.99.9.zip'
Content type 'application/zip' length 1158688 bytes (1.1 MB)
downloaded 1.1 MB
package ‘DelayedDataFrame’ successfully unpacked and MD5 sums checked
Might R Under Development be made an option the user of RStudio Cloud could choose?