Building FFTW tries to download to read-only folder

[BeastyBlacksmith]

running ]build FFTW in a clean environment brought me this error:

Error building `FFTW`: 
│ [ Info: Downloading https://github.com/JuliaBinaryWrappers/FFTW_jll.jl/releases/download/FFTW-v3.3.9+0/FFTW.v3.3.9.x86_64-linux-gnu.tar.gz to /usr/home/christ/.julia/packages/FFTW/xi4tZ/deps/usr/downloads/FFTW.v3.3.9.x86_64-linux-gnu.tar.gz...
│ ERROR: LoadError: LoadError: Could not download https://github.com/JuliaBinaryWrappers/FFTW_jll.jl/releases/download/FFTW-v3.3.9+0/FFTW.v3.3.9.x86_64-linux-gnu.tar.gz to /usr/home/christ/.julia/packages/FFTW/xi4tZ/deps/usr/downloads/FFTW.v3.3.9.x86_64-linux-gnu.tar.gz:
│ ErrorException("")

This seems to me as if it tries to store the binary in the .julia/packages folder which is read-only AFAIK.
Could also be an issue with BinaryBuilder

julia> versioninfo()
Julia Version 1.1.1
Commit 55e36cc308 (2019-05-16 04:10 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, ivybridge)
Environment:
  JULIA_EDITOR = atom  -a
  JULIA_NUM_THREADS = 4

[stevengj]

Seems like this may be a bug in BinaryProvider.jl, can you file the issue there?

[BeastyBlacksmith]

done