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Re: Missing `alloca` symbol - help?

On 10/15/2018 9:20 PM, Murray Christopherson wrote:
> I'm not certain this is a problem with Cygwin, but I am unable to find any
> issue by looking over the project in question, so I thought I'd ask. Is
> this an obvious bug, either in Cygwin or the project itself?
> [...]
> # Observed result
> Fails to install. Particularly, the error output makes multiple mentions of
> `undefined reference to `alloca'` during linking (full error log at
> https://github.com/theacodes/cmarkgfm/issues/13).
> # Notes
> As far as I can tell, `alloca` is a standard Unix function (though
> deprecated). Also, in Cygwin, `/usr/includes/alloca/h` exists, suggesting
> the function _should_ exist to be linked without further packages?

alloca is defined in /usr/include/alloca.h as a macro expanding to 
__builtin_alloca.  The linking error you report suggests that there's a missing 
"#include <alloca.h>" in the source code that's being compiled.  This is also 
confirmed by the gcc warnings in your full log.