Error in installing Mongo package on Mac OS

[Roger Whitney]

I am new to Julia and am trying to use the Mongo package. I am using Julia 0.4.6 on Mac OS 10.11.6. When I try to add (or build) the package using Pkg.add("Mongo") or Pkg.build("Mongo")I get the error:

"Error: Cannot install mongo-c because conflicting formulae are installed.

  libbson: because mongo-c installs the libbson headers

Please `brew unlink libbson` before continuing.

Unlinking removes a formula's symlinks from /Users/whitney/.julia/v0.4/Homebrew/deps/usr. You can

link the formula again after the install finishes. You can --force this

install, but the build may fail or cause obscure side-effects in the

resulting software."

I then tried to unlink libbson using: Homebrew.brew(`unlink libbson`) and then tried building Mongo again, but had the same error.

Has anyone been able to install the Mongo package on a Mac?  Any help would be appreciated. There was a thread on the Mongo package about a year ago which ended in people claiming they were able to install the package but errors there seemed different. 

[Tony Kelman]

Does Pkg.checkout("Homebrew") and restarting Julia make any difference? If not, go back to the tagged release with Pkg.free("Homebrew")

[Roger Whitney]

I get another error:

"Error: Operation already in progress for pkg-config

Another active Homebrew process is already using pkg-config.

Please wait for it to finish or terminate it to continue."

I checked. There was only one Julia process running and no separate Homebrew process running. 

[Tony Kelman]

Homebrew might be using a lock file or something that has gotten in a strange state. You might want to open an issue on github at JuliaLang/Homebrew.jl and cc @staticfloat who is the primary author of that package.

[Tony Kelman]

Looks like this was reported at https://github.com/JuliaLang/Homebrew.jl/issues/139 - might want to click "subscribe" there or leave a comment saying you're also having the same issue, in case more information is needed to debug what's happening.