Macros: Can't esc names in global assignments

[fcard]

macro m()
  :(global $(esc(:x)) = 1)
end

julia> @m
ERROR: syntax: malformed expression

julia> @macroexpand @m

signal (11): Segmentation fault
in expression starting at no file:0
htable_new at /home/fabio/Source/Git/Languages/julia/src/support/htable.c:34
builtin_arg_counts at /home/fabio/Source/Git/Languages/julia/usr/bin/../lib/libjulia.so.0.7 (unknown line)
Allocations: 684912 (Pool: 684701; Big: 211); GC: 0
[1]    6419 segmentation fault  julia

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0.7.0-DEV.2278
Works in 0.7.0-DEV.369

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Crossref JuliaGraphics/Gtk.jl#324