# FFTW fails to build
**URL:** https://discourse.julialang.org/t/fftw-fails-to-build/41392
**Category:** General Usage
**Tags:** question
**Created:** [June 14, 2020, 5:33pm UTC](https://discourse.julialang.org/t/fftw-fails-to-build/41392 "2020-06-14T17:33:19Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@ctkelley](https://discourse.julialang.org/u/ctkelley)
#### Post date: [June 14, 2020, 5:33pm UTC](https://discourse.julialang.org/t/fftw-fails-to-build/41392/1 "2020-06-14T17:33:20Z")
I did an
> ] update
and FFTW failed with this message
> (@v1.4) pkg\> build FFTW
>
> Building FFTW → `~/.julia/packages/FFTW/kcXL6/deps/build.log`
> ┌ Error: Error building `FFTW`:
> │ ERROR: LoadError: ArgumentError: Package LinearAlgebra not found in current path:
> │ - Run `import Pkg; Pkg.add("LinearAlgebra")` to install the LinearAlgebra package.
> │
> │ Stacktrace:
> │ [1] require(::Module, ::Symbol) at ./loading.jl:892
> │ [2] include(::String) at ./client.jl:439
> │ [3] top-level scope at none:5
> │ in expression starting at /Users/ctk/.julia/packages/FFTW/kcXL6/deps/build.jl:1
> └@Pkg.Operations/Users/julia/buildbot/worker/package\_macos64/build/usr/share/julia/stdlib/v1.4/Pkg/src/Operations.jl:899
so I did (LinearAlgebra was already installed, but I tried again anyhow)
> ] add LinearAlgebra
> ] build LinearAlgebra
> ] build FFTW
and got the same error message. Any ideas?
---
### Author:  [@ctkelley](https://discourse.julialang.org/u/ctkelley)
#### Post date: [June 14, 2020, 5:44pm UTC](https://discourse.julialang.org/t/fftw-fails-to-build/41392/2 "2020-06-14T17:44:01Z")
Never mind. I did
> ] rm FFTW
> ] add FFTW
restarted Julia and typed this in the REPL
> \> using FFTW
got (no mention of LinearAlgebra)
> ERROR: LoadError: FFTW is not properly installed. Please run Pkg.build(“FFTW”) and restart Julia.
Did as advised and all seems to be well. Is there a reason my first attempt failed?