load_all() fails cryptically for Matrix

[MichaelChirico]

I see the following (truncated) output for pkgload::load_all("Matrix") for the package cloned from the cran/Matrix GitHub repo:

─  DONE (Matrix)
Error in readChar(con, 5L, useBytes = TRUE) : cannot open the connection
In addition: Warning message:
In readChar(con, 5L, useBytes = TRUE) :
  cannot open compressed file '', probable reason 'No such file or directory'

This must be some sort of compilation issue;

1. Is load_all() expected to work for all (non-default) packages, including recommended priority?
2. Can this error be improved?