import Distributed; Distributed.@everywhere x = 2 does not work

[cossio]

This works fine:

using Distributed; @everywhere x = 2

but

import Distributed; Distributed.@everywhere x = 2
# ERROR: LoadError: UndefVarError: @everywhere not defined

gives an error.

[vchuravy]

julia> import Distributed; Distributed.@everywhere x = 2
ERROR: LoadError: UndefVarError: @everywhere not defined
in expression starting at C:\cygwin\home\Administrator\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.0\Distributed\src\macros.jl:182

Looks like the macro

julia/stdlib/Distributed/src/macros.jl

Line 182 in 2346be8

return esc(:(@everywhere $procs() $ex))

assumes that @everywhere is in the namespace.

d61b054 and x-ref 23164

[ibadr]

Also, this fails with the same error, despite using Distributed

const parallel = true
if !parallel
    println("not parallel")
else
    using Distributed; @everywhere x = 2
    println("parallel")
end

[ibadr]

For now, this slight tweak works for me

const parallel = true
if !parallel
    println("not parallel")
else
    using Distributed
    Distributed.remotecall_eval(Main, procs(), :(x = 2)) # in lieu of @everywhere x = 2
    println("parallel")
end

[martinholters]

@ibadr That's a different issue: The parser tries to expand the macro before the using is evaluated, because the parser processes the whole if/else/end before anything of it is evaluated.

[fredrikekre]

GitHub doesn't autoclose issues from commit messages any more? fixed by #32144