Bug 1327 – Long environment variable value causes link failure.

Hi I had some problems getting DMD to play nicely with cygwin. It turns out the problem was down to a long environment variable value. As a newcomer to D I was very confused. It was not at all obvious what was happening. Regards, Bruce. F:\projects\Agenda>c:\cygwin\bin\make dtest2 dmc hello.d -o hello c:\dmd\bin\..\..\dm\bin\link.exe hello,,,user32+kernel32/noi; c:\dmd\bin\..\..\dm\bin\link.exe hello,,,user32+kernel32/noi; hello.d: hello.d: link hello+hello,,,user32+kernel32/noi; F:\projects\Agenda>set GCCINCDIR="C:\cygwin\usr\include;C:\cygwin\usr\include\sy s;C:\cygwin\usr\include\w32api;C:\cygwin\usr\local\i686-pc-cygwin\include;C:\cyg win\usr\local\i686-pc-cygwin\include\sys;C:\cygwin\usr\include\c++\3.4.4;C:\cygw in\usr\include\c++\3.4.4\i686-pc-cygwin;C:\cygwin\usr\include\c++\3.4.4\i686-pc- cygwin\bits;C:\cygwin\lib\gcc-lib\i686-pc-cygwin\3.4.4\include;C:\cygwin\usr\inc lude;C:\cygwin\usr\include\sys;C:\cygwin\usr\include\w32api;C:\cygwin\usr\local\ i686-pc-cygwin\include;C:\cygwin\usr\local\i686-pc-cygwin\include\sys;C:\cygwin\ usr\include\c++\3.4.4;C:\cygwin\usr\include\c++\3.4.4\i686-pc-cygwin;C:\cygwin\u sr\include\c++\3.4.4\i686-pc-cygwin\bits;C:\cygwin\lib\gcc\i686-pc-cygwin\C:\cyg win\usr\include;C:\cygwin\usr\include\sys;C:\cygwin\usr\include\w32api;C:\cygwin \usr\local\i686-pc-cygwin\include;C:\cygwin\usr\local\i686-pc-cygwin\include\sys ;C:\cygwin\usr\include\c++\3.4.4;C:\cygwin\usr\include\c++\3.4.4\i686-pc-cygwin; C:\cygwin\usr\include\c++\3.4.4\i686-pc-cygwin\bits;C:\cygwin\lib\gcc-lib\i686-p c-cygwin\3.4.4\include;C:\cygwin\usr\include;C:\cygwin\usr\include\sys;C:\cygwin \usr\include\w32api;C:\cygwin\usr\local\i686-pc-cygwin\include;C:\cygwin\usr\loc al\i686-pc-cygwin\include\sys;C:\cygwin\usr\include\c++\3.4.4;C:\cygwin\usr\incl ude\c++\3.4.4\i686-pc-cygwin;C:\cygwin\usr\include\c++\3.4.4\i686-pc-cygwin\bits \include;C:\cygwin\lib\gcc\i686-pc-cygwin\3.4.4\include\c++;;C:\cygwin\lib\gcc\i 686-pc-cygwin\3.4.4\include\c++\i686-pc-cygwin;C:\cygwin\lib\gcc\i686-pc-cygwin\ 3.4.4\include" F:\projects\Agenda>c:\cygwin\bin\make dtest2 dmc hello.d -o hello c:\dmd\bin\..\..\dm\bin\link.exe hello,,,user32+kernel32/noi; OPTLINK (R) for Win32 Release 7.50B1 Copyright (C) Digital Mars 1989 - 2001 All Rights Reserved phobos.lib Warning 2: File Not Found phobos.lib OPTLINK : Warning 23: No Stack hello.obj(hello) Error 42: Symbol Undefined _main hello.obj(hello) Error 42: Symbol Undefined __acrtused_con OPTLINK : Warning 134: No Start Address --- errorlevel 2 hello.d: --- errorlevel 2 make: *** [dtest2] Error 2

I can confirm this also happens on the latest version (v2.002)

Ouch. That must have taken ages to figure out. Actually it seems to be related to both the variable name and its value. For instance "XCCINCDIR" worked ok, and many values of GCCINCDIR are ok for me. But other variables caused the problem too, like "FOOINCDIR". I can't really determine a pattern. In any event you should probably use 'dmd' to compile D code and not 'dmc' (which is a C++ compiler) ;-)

Keep the version at the oldest, not the newest, relevant value, please.

OPTLINK doesn't see the LIB variable if the environment is too big. In my case it starts to misbehave if the environment is longer than about 8K, but I guess the exact size varies depending on where LIB is in the environment. This affects D2 as well.

Since it's an OPTLINK-specific issue, and OPTLINK is now open source, transferring it to https://github.com/DigitalMars/optlink/issues/25

*** Issue 12054 has been marked as a duplicate of this issue. ***