`touch`ing package sources only works on Windows?

General Usage
3

Thanks for looking.
In two Linux and one Mac I got the same error and this was triggered by a Mac user who reported me the error. It seems that it’s because the package is installed read-only. But then why it works trough run()?

julia> pathof(GMT)
"/home/jluis/.julia/packages/GMT/fORs3/src/GMT.jl"

julia> run(`whoami`)
jluis
Process(`whoami`, ProcessExited(0))

julia> run(`ls -al /home/jluis/.julia/packages/GMT/fORs3/src/GMT.jl`)
-r--r--r--. 1 jluis jluis 9185 Mar 16 08:31 /home/jluis/.julia/packages/GMT/fORs3/src/GMT.jl
Process(`ls -al /home/jluis/.julia/packages/GMT/fORs3/src/GMT.jl`, ProcessExited(0))