msys-2.0.dl to cygwin1.dll switch patches by lygstate · Pull Request #334 · msys2/msys2-runtime

lygstate · 2026-04-07T09:54:18Z

This MR reorder the patches, so we can transition from msys-2.0.dl to cygwin1.dll.

First, we revert the patches that rename cygwin1.dll to msys-2.0.dll

Revert "strace.cc: Don't set MSYS=noglob"
Revert "Rename dll from cygwin to msys"
Revert "Fix msys library name in import libraries"
Revert "uname: allow setting the system name to CYGWIN"
Revert "Add functionality for changing OS name via MSYSTEM environment variables."

NOTE: these reverts can be dropped in the next rebase

Then add patches that support for transition msys-2.0.dl to cygwin1.dll.

Add functionality for changing OS name via MSYSTEM environment variables.
Support for both cygwin and msys2
Support for both MSYS and CYGWIN environment variable
strace.cc: Don't set CYGWIN=noglob
Convert to use msys'style named pipe

The last two patch is to keep the orignal `Rename dll from cygwin to msys`

Rename dll from cygwin to msys
Fix msys library name in import libraries

With the last two patch, the built dll will be msys-2.0.dll.
Without the last two patch, the built dll will be cygwin1.dll.

So we can bootstrap msys-2.0.dll to cygwin1.dll in MSYS2-packages in a single code base.

This reverts commit 97de8ba.

This reverts commit dae2b5b.

dscho · 2026-04-08T09:03:34Z

This MR reorder the patches, so we can transition from msys-2.0.dl to cygwin1.dll.

I am unaware of such a plan.

I mean, I can imagine that there is a ton of benefit to reduce the difference between the MSYS2 runtime and the Cygwin runtime to the bare minimum, to the point where even the path translation (which is probably the most distinguishing feature of the MSYS2 runtime) would be upstreamed to the Cygwin runtime as an opt-in, e.g. via a flag in /etc/nsswitch.conf. That would generate synergies between the Cygwin and the MSYS2 project, making it even easier to help each other out in meaningful ways. I'm all for going this direction.

At the same time, I am convinced that such a plan can only succeed by first building consensus about the direction, and I haven't seen such a discussion. Have I missed it?

lygstate · 2026-04-08T09:11:20Z

This MR reorder the patches, so we can transition from msys-2.0.dl to cygwin1.dll.

I am unaware of such a plan.

I mean, I can imagine that there is a ton of benefit to reduce the difference between the MSYS2 runtime and the Cygwin runtime to the bare minimum, to the point where even the path translation (which is probably the most distinguishing feature of the MSYS2 runtime) would be upstreamed to the Cygwin runtime as an opt-in, e.g. via a flag in /etc/nsswitch.conf. That would generate synergies between the Cygwin and the MSYS2 project, making it even easier to help each other out in meaningful ways. I'm all for going this direction.

At the same time, I am convinced that such a plan can only succeed by first building consensus about the direction, and I haven't seen such a discussion. Have I missed it?

This is my local draft work that can transition from transition msys-2.0.dl to cygwin1.dll, post here for discussion.

This is just barelly bootstrap msys-2.0.dll into cygwin1.dll, other things I am not considered yet.

The most important part of msys2 I think is pacman, othere things(the runtime differencies) is minimal now.

And indeed pacman not working in cygwin at all.

dscho · 2026-04-08T09:28:48Z

+      char *name_to_compare = rva (PSTR, map ?: (char *) hm, pd->Name - delta);
+      bool not_msys2 = !ascii_strcasematch (name_to_compare, "msys-2.0.dll");
+      bool not_cygwin = !ascii_strcasematch (name_to_compare, "cygwin1.dll");


Up until this point, I see the keying factor to be the presence of the MSYS and the CYGWIN environment variable. It is not quite clear what this MR wants to do if both are set, but it is clear that it wants to trigger the MSYS2 vs Cygwin code paths depending on the presence of either environment variable.

This hunk, however, tells a very different story (and one that I could understand much better): whether to run in MSYS2 or in Cygwin mode is keyed by the name of the DLL.

It sounds a bit fraught with peril to have both mechanisms. It would probably be a lot more desirable to key only on one of the two, not on both.

This is a temporary patch that bootstrap from "msys-2.0.dll" to "cygwin1.dll", once the bootstrap finished. we can then revert this patch directly.

dscho · 2026-04-08T09:31:11Z

-/* Commit message for this code was:
-"* strace.cc (create_child): Set CYGWIN=noglob when starting new process so that
-
-  Cygwin will leave already-parsed the command line alonw."
-
-  I can see no reason for it and it badly breaks the ability to use
-  strace.exe to investigate calling a Cygwin program from a Windows
-  program, for example:
-  strace mingw32-make.exe
-  .. where mingw32-make.exe finds sh.exe and uses it as the shell.
-  The reason it badly breaks this use-case is because dcrt0.cc depends
-  on globbing to happen to parse commandlines from Windows programs;
-  irrespective of whether they contain any glob patterns or not.
-
-  See quoted () comment:
-  "This must have been run from a Windows shell, so preserve
-     quotes for globify to play with later."
-
-  const char *cygwin_env = getenv ("MSYS");
+
+#if 0
+  const char *cygwin_env = getenv ("CYGWIN");
  const char *space;

-  if (cygwin_env && strlen (cygwin_env) <= 256) // sanity check
+  if (cygwin_env && strlen (cygwin_env) <= 256) /* sanity check */
    space = " ";
  else
    space = cygwin_env = "";
-  char *newenv = (char *) malloc (sizeof ("MSYS=noglob")
+  char *newenv = (char *) malloc (sizeof ("CYGWIN=noglob")
 				  + strlen (space) + strlen (cygwin_env));
-  sprintf (newenv, "MSYS=noglob%s%s", space, cygwin_env);
+  sprintf (newenv, "CYGWIN=noglob%s%s", space, cygwin_env);
  _putenv (newenv);
-*/
+#endif
+


That's a lot of dead code. It would make more sense to investigate properly what the original commit tried to do, why it was wrong, and then to drop that part altogether. But that should most likely come as a separate Merge Request.

I do this for reduce MSYS presence in code-base, as it's commted code, so I use #if 0, as this can be accepted, I'll create separte MR for it.

lygstate · 2026-04-08T09:58:15Z

I mean, I can imagine that there is a ton of benefit to reduce the difference between the MSYS2 runtime and the Cygwin runtime to the bare minimum, to the point where even the path translation (which is probably the most distinguishing feature of the MSYS2 runtime) would be upstreamed to the Cygwin runtime as an opt-in, e.g. via a flag in /etc/nsswitch.conf. That would generate synergies between the Cygwin and the MSYS2 project, making it even easier to help each other out in meaningful ways. I'm all for going this direction.

The main target of this MR is rename rename msys-2.0.dll back to cygwin1.dll, and convert msys- prefix ino cyg, so that the whole MYS2-packages can remove many patches, the upstream patches of msys2-runtime into cygwin did not conflict with this MR, as this MR did not change the runtime much.

This reverts commit a32cbc8.

…t variables." This reverts commit b91f792.

…les. allow setting the system name to CYGWIN We are currently trying to move our cygwin build environment closer to cygwin and some autotools/bash based build systems call "uname -s" to figure out the OS and in many cases only handle the cygwin case, so we have to patch them. With this instead of patching we can set MSYSTEM=CYGWIN and change uname output that way. The next step would be to always output CYGWIN in an msys env by default, but for now this allows us to get rid of all the patches without affecting users.

Changes of winsup/cygwin/environ.cc is split from "Add functionality for changing OS name via MSYSTEM environment variables." Changes of winsup/cygwin/exceptions.cc, winsup/utils/mingw/cygcheck.cc is split from "Rename dll from cygwin to msys" known_env_vars is sorted, update it

Commit message for this code was: * strace.cc (create_child): Set CYGWIN=noglob when starting new process so that Cygwin will leave already-parsed the command line alonw." I can see no reason for it and it badly breaks the ability to use strace.exe to investigate calling a Cygwin program from a Windows program, for example: strace mingw32-make.exe .. where mingw32-make.exe finds sh.exe and uses it as the shell. The reason it badly breaks this use-case is because dcrt0.cc depends on globbing to happen to parse commandlines from Windows programs; irrespective of whether they contain any glob patterns or not. See quoted () comment: "This must have been run from a Windows shell, so preserve quotes for globify to play with later."

This is split from "Rename dll from cygwin to msys"

This reverts commit 3e941b8.

This is a prepare for merge msys2 into cygwin

This is for bootstrap building msys2 as cygwin1.dll This can be rebased before "Rename dll from cygwin to msys"

lygstate added 2 commits April 7, 2026 16:35

Revert "strace.cc: Don't set MSYS=noglob"

6b394a8

This reverts commit 97de8ba.

Revert "Rename dll from cygwin to msys"

d2fdc8a

This reverts commit dae2b5b.

dscho reviewed Apr 8, 2026

View reviewed changes

lygstate marked this pull request as draft April 8, 2026 09:55

lygstate and others added 3 commits April 8, 2026 18:06

Revert "uname: allow setting the system name to CYGWIN"

1cc96c7

This reverts commit a32cbc8.

Revert "Add functionality for changing OS name via MSYSTEM environmen…

f4de5f4

…t variables." This reverts commit b91f792.

lygstate mentioned this pull request Apr 8, 2026

Msys2 3.6.7 rework the exist patches to be more minimal #335

Closed

Alexpux and others added 4 commits April 8, 2026 19:19

Convert to use msys'style named pipe

a9ea83f

This is split from "Rename dll from cygwin to msys"

Rename dll from cygwin to msys

9482d18

lygstate force-pushed the msys2-to-cygwin-3.6.7 branch from f5f360c to 95177a1 Compare April 8, 2026 11:31

lygstate added 4 commits April 10, 2026 03:47

Revert "Add support for MSYS environment variable instead of CYGWIN"

88b485b

This reverts commit 3e941b8.

Support for both MSYS and CYGWIN environment variable

86ad1e0

This is a prepare for merge msys2 into cygwin

Revert hookapi.cc of "Rename dll from cygwin to msys"

2ea6dbc

hookapi.c: Support for both cygwin and msys2 for bootstrap

fd5ce30

This is for bootstrap building msys2 as cygwin1.dll This can be rebased before "Rename dll from cygwin to msys"

lygstate force-pushed the msys2-to-cygwin-3.6.7 branch from 95177a1 to fd5ce30 Compare April 10, 2026 00:45

lygstate mentioned this pull request Apr 27, 2026

Msys2 3.6.9 patches reorder #337

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msys-2.0.dl to cygwin1.dll switch patches#334

msys-2.0.dl to cygwin1.dll switch patches#334
lygstate wants to merge 13 commits intomsys2:msys2-3.6.7from
lygstate:msys2-to-cygwin-3.6.7

lygstate commented Apr 7, 2026 •

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lygstate commented Apr 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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First, we revert the patches that rename cygwin1.dll to msys-2.0.dll

Then add patches that support for transition msys-2.0.dl to cygwin1.dll.

The last two patch is to keep the orignal Rename dll from cygwin to msys

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lygstate commented Apr 7, 2026 •

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The last two patch is to keep the orignal `Rename dll from cygwin to msys`

lygstate commented Apr 8, 2026 •

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