https://issues.dlang.org/show_bug.cgi?id=19146

          Issue ID: 19146
           Summary: std.process.spawnProcess: Set signal handlers are
                    reset to SIG_DFL before fork
           Product: D
           Version: D2
          Hardware: All
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: kubo39@gmail.com

It's a possibility that rewriteing global variables may be performed by singal
handler,So set signal handlers are reset to SIG_DFL.
In order to prevent race condition, it is necessary to mask signals once in the
parent process before fork.

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