warn if General is installed via the old slow methods (#4022)

* warn if General is installed via the old slow methods

* add env var disable

src/Registry/Registry.jl

@@ -447,6 +447,15 @@ function update(regs::Vector{RegistrySpec}; io::IO=stderr_f(), force::Bool=true,
  registry_update_log[string(reg.uuid)] = now()
  @label done_tarball_read
  else
+ if reg.name == "General" && Base.get_bool_env("JULIA_PKG_GEN_REG_FMT_CHECK", true)
+ @info """
+ The General registry is installed via unpacked tarball.
+ Consider reinstalling it via the newer faster direct from
+ tarball format by running:
+ pkg> registry rm General; registry add General
+
+ """ maxlog=1
+ end
  mktempdir() do tmp
  try
  download_verify_unpack(url, nothing, tmp, ignore_existence = true, io=io)
@@ -465,6 +474,14 @@ function update(regs::Vector{RegistrySpec}; io::IO=stderr_f(), force::Bool=true,
  end
  elseif isdir(joinpath(reg.path, ".git"))
  printpkgstyle(io, :Updating, "registry at " * regpath)
+ if reg.name == "General" && Base.get_bool_env("JULIA_PKG_GEN_REG_FMT_CHECK", true)
+ @info """
+ The General registry is installed via git. Consider reinstalling it via
+ the newer faster direct from tarball format by running:
+ pkg> registry rm General; registry add General
+
+ """ maxlog=1
+ end
  LibGit2.with(LibGit2.GitRepo(reg.path)) do repo
  if LibGit2.isdirty(repo)
  push!(errors, (regpath, "registry dirty"))