# Error precompiling CSV and SentinelArrays
**URL:** https://discourse.julialang.org/t/error-precompiling-csv-and-sentinelarrays/98274
**Category:** New to Julia
**Tags:** package, precompilation
**Created:** [May 3, 2023, 6:55pm UTC](https://discourse.julialang.org/t/error-precompiling-csv-and-sentinelarrays/98274 "2023-05-03T18:55:10Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@burtmonroe](https://discourse.julialang.org/u/burtmonroe)
#### Post date: [May 3, 2023, 6:55pm UTC](https://discourse.julialang.org/t/error-precompiling-csv-and-sentinelarrays/98274/1 "2023-05-03T18:55:10Z")
Hi:
Trying to run the first notebook (Data) in the Julia Academy Data Science course and it fails immediately on the `using CSV` command, failing to precompile SentinelArrays. I’ve seen there were problems people had last year with CSV when upgrading to 1.7, but I’m running Julia 1.8.5. Any suggestions?
```julia
┌ Info: Precompiling CSV [336ed68f-0bac-5ca0-87d4-7b16caf5d00b]
└ @ Base loading.jl:1664
ERROR: LoadError: ccall method definition: argument 1 type doesn't correspond to a C type
Stacktrace:
[1] top-level scope
@ ~/.julia/packages/SentinelArrays/Uq3RP/src/SentinelArrays.jl:209
[2] include
@ ./Base.jl:419 [inlined]
[3] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt64}}, source::String)
@ Base ./loading.jl:1554
[4] top-level scope
@ stdin:1
in expression starting at /Users/burtmonroe/.julia/packages/SentinelArrays/Uq3RP/src/SentinelArrays.jl:1
in expression starting at stdin:1
ERROR: LoadError: Failed to precompile SentinelArrays [91c51154-3ec4-41a3-a24f-3f23e20d615c] to /Users/burtmonroe/.julia/compiled/v1.8/SentinelArrays/jl_puVCGx.
Stacktrace:
[1] error(s::String)
@ Base ./error.jl:35
[2] compilecache(pkg::Base.PkgId, path::String, internal_stderr::IO, internal_stdout::IO, keep_loaded_modules::Bool)
@ Base ./loading.jl:1707
[3] compilecache
@ ./loading.jl:1651 [inlined]
[4] _require(pkg::Base.PkgId)
@ Base ./loading.jl:1337
[5] _require_prelocked(uuidkey::Base.PkgId)
@ Base ./loading.jl:1200
[6] macro expansion
@ ./loading.jl:1180 [inlined]
[7] macro expansion
@ ./lock.jl:223 [inlined]
[8] require(into::Module, mod::Symbol)
@ Base ./loading.jl:1144
[9] include
@ ./Base.jl:419 [inlined]
[10] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt64}}, source::Nothing)
@ Base ./loading.jl:1554
[11] top-level scope
@ stdin:1
in expression starting at /Users/burtmonroe/.julia/packages/CSV/Zl2ww/src/CSV.jl:1
in expression starting at stdin:1
Failed to precompile CSV [336ed68f-0bac-5ca0-87d4-7b16caf5d00b] to /Users/burtmonroe/.julia/compiled/v1.8/CSV/jl_tOEChC.
Stacktrace:
[1] error(s::String)
@ Base ./error.jl:35
[2] compilecache(pkg::Base.PkgId, path::String, internal_stderr::IO, internal_stdout::IO, keep_loaded_modules::Bool)
@ Base ./loading.jl:1707
[3] compilecache
@ ./loading.jl:1651 [inlined]
[4] _require(pkg::Base.PkgId)
@ Base ./loading.jl:1337
[5] _require_prelocked(uuidkey::Base.PkgId)
@ Base ./loading.jl:1200
[6] macro expansion
@ ./loading.jl:1180 [inlined]
[7] macro expansion
@ ./lock.jl:223 [inlined]
[8] require(into::Module, mod::Symbol)
@ Base ./loading.jl:1144
[9] eval
@ ./boot.jl:368 [inlined]
[10] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
@ Base ./loading.jl:1428
```
---
### Author:  [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)
#### Post date: [May 3, 2023, 7:43pm UTC](https://discourse.julialang.org/t/error-precompiling-csv-and-sentinelarrays/98274/2 "2023-05-03T19:43:24Z")
> [@burtmonroe](#):
>
> Julia Academy Data Science
Are you activating the environment? It looks like a Manifest.toml is committed to github. You should try and use those exact versions.
---
### Author:  [@burtmonroe](https://discourse.julialang.org/u/burtmonroe)
#### Post date: [May 3, 2023, 8:31pm UTC](https://discourse.julialang.org/t/error-precompiling-csv-and-sentinelarrays/98274/3 "2023-05-03T20:31:04Z")
I _thought_ I was following the instructions to do so (with `instantiate`), and that seemed to use the right versions, but maybe there’s a step I’m missing with regard to “activating the environment.”
In any case, short term, the error was eliminated by updating the packages – _not_ using the exact versions. (And the notebook is a couple of years old I now see, so it’s probably no surprise that it may now have some issues.)
Thanks!