Fetching anything segfaults when Pextlib calls system Tcl

[Joshua Root]

> Thread 0 Crashed:  Dispatch queue: com.apple.main-thread
> 0   libSystem.B.dylib             	0x00007fff85270c00 strlen + 16
> 1   Tcl                           	0x000000010008a350 Tcl_SetResult + 83
> 2   Pextlib.dylib                 	0x000000010070e617 SetResultFromCurlErrorCode + 103
> 3   Pextlib.dylib                 	0x000000010070f47c CurlFetchCmd + 1420
> 4   Pextlib.dylib                 	0x000000010070f788 CurlCmd + 184

The relevant code is:
<https://trac.macports.org/browser/tags/release_2_1_2/base/src/pextlib1.0/curl.c#L81>

Crashing where and how it does would suggest that curl_easy_strerror is
somehow returning either a bad pointer or an unterminated string. If you
build base from source you can add some debug printfs to see what the
error code is at least, and which operation it comes from.

Given that you're the first to report this problem AFAIK (#31472 is
different), I wouldn't rule out something like bad RAM or disk corruption.

- Josh