Mmap bus error

[quinnj]

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|__/                   |  x86_64-apple-darwin16.7.0

julia> using Mmap

julia> a = Mmap.mmap("foo2", Vector{NTuple{1, Int8}}, 1, 0)
1-element Array{Tuple{Int8},1}:
Bus error: 10

Also happens for simple structs like struct Wrapper; x::Int; end. I plan on taking a look at this to see what's going on, but if anyone else has any ideas, please share in the mean time.

[JeffBezanson]

Works for me.

[jpsamaroo]

I also got a Bus error (on Linux, Julia Version 0.7.0-beta2.78), but that was because the file was empty. Adding 10M to the file with dd fixed it. If that doesn't work, you could try running under strace (or whatever the equivalent is on OSX, dtrace maybe?).

[xgdgsc]

I get bus error if specified shape larger than the file size. Julia would crash. Is it possible to make it not crash the session and only report an error? I think it could check filesize first.

[xgdgsc]

using Mmap
A = rand(1:0.5:20, 5, 30)
s = open("mmap.bin", "w+")
write(s, A)
close(s)
B = Mmap.mmap(open("mmap.bin"), Matrix{Float64}, (4096,30))

This would crash with Bus Error on Ubuntu 16.04 with julia 1.3.1 . While on Win 10 it only prints an error.

[Moelf]

Does this still crash for some people?

[xgdgsc]

The original poster code doesn' t crash. My code in the comment above still crashes in Ubuntu 20.04, julia 1.6 and 1.7.

[vtjnash]

As mentioned above #28245 (comment), there is a missing call to open(identity, "foo2", "w") in the MWE