When trying to install a specific version of any package that's not the latest version, it errors with "couldn't find package".

Fails

devtools::install_version("BiocParallel", version="1.14.1", repos=c("https://bioconductor.org/packages/3.7/bioc"))

Works, since it's the latest

devtools::install_version("BiocParallel", version="1.14.2", repos=c("https://bioconductor.org/packages/3.7/bioc"))

Looking at the devtools source code, it fails due to a missing file in the archive: https://bioconductor.org/packages/3.7/bioc/src/contrib/Meta/archive.rds

Other CRAN archives seem to have this file: https://cloud.r-project.org/src/contrib/Meta/archive.rds

This affects Packrat's ability to save the source code in a project. (nvm: Packrat doesn't use this, just devtools)

packrat::init()
install.packages("devtools")
devtools::install_bioc("BiocParallel")
packrat::snapshot()

Is it possible to get the metadata file added?

You could just use switcher A: Looking for the source for IRanges 2.8.1, S4Vectors 0.12.1 and XVector 0.14.0