Dr.Memory crash on Windows Azure (Appveyor)

Reporting as stated in the error message.

When running the unit tests of my program through Dr. Memory on http://www.appveyor.com/ I get the crash below

Full log where crash occurred:
https://ci.appveyor.com/project/JoakimSoderberg/cargo/build/1.0.98

To compile your own version read the README.md:
https://github.com/JoakimSoderberg/cargo/tree/variadic

To compile exactly as when the crash occured follow the steps in the appveyor config:
https://github.com/JoakimSoderberg/cargo/blob/variadic/appveyor.yml

The exact git version that caused the crash:

``` bash
git clone -q --branch=variadic git://github.com/JoakimSoderberg/cargo.git C:\projects\cargo
git checkout -qf 3019887e75fce509c4cb30ba24b9520b8e73ba2e
```

The code line that the crash trace back refers to can be found here:
https://github.com/JoakimSoderberg/cargo/blob/3019887e75fce509c4cb30ba24b9520b8e73ba2e/cargo.c#L596

```
~~Dr.M~~ # 2 _cargo_parse_option [c:\projects\cargo\cargo.c:596]
```

Crash excerpt:

```
ctest --output-on-failure
Test project C:/projects/cargo/build
Start 1: TEST_no_args_bool_option_memchk
1/22 Test #1: TEST_no_args_bool_option_memchk ...................***Failed 4.50 sec
~~Dr.M~~ Dr. Memory version 1.8.0
~~Dr.M~~ Running "C:/projects/cargo/build/bin/Debug/cargo_tests.exe TEST_no_args_bool_option"
~~Dr.M~~
~~Dr.M~~ Error #1: UNADDRESSABLE ACCESS: reading 0xcccccccc-0xcccccccd 1 byte(s)
~~Dr.M~~ # 0 MSVCR120D.dll!mbctombb_l +0x4f53 (0x748efb53 )
~~Dr.M~~ # 1 MSVCR120D.dll!fprintf +0x285 (0x74878ff6 )
~~Dr.M~~ # 2 _cargo_parse_option [c:\projects\cargo\cargo.c:596]
~~Dr.M~~ # 3 cargo_parse [c:\projects\cargo\cargo.c:1278]
~~Dr.M~~ # 4 TEST_no_args_bool_option [c:\projects\cargo\cargo.c:2103]
~~Dr.M~~ # 5 main [c:\projects\cargo\cargo.c:2610]
~~Dr.M~~ Note: @0:00:01.312 in thread 2992
~~Dr.M~~ Note: instruction: movsx (%eax) -> %ecx

~~Dr.M~~ Fetching 1 symbol files...
~~Dr.M~~ [1/1] Fetching symbols for C:\Windows\SYSTEM32\MSVCR120D.dll
~~Dr.M~~ Fetched 0 symbol files successfully
~~Dr.M~~ WARNING: application exited with abnormal code 0xffffffff
```