I have no idea if a Cygwin app can be made to directly interact with VBoxXPCOMC.dll, but this at least lets compilation of vbox finish rather than requiring me to ./configure --without-vbox. * src/vbox/vbox_XPCOMCGlue.c (DYNLIB_NAME): Assume .dll under cygwin. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- Although I'm tempted to push this under the build-breaker rule, and although I suspect no one else is trying to build libvirt on cygwin, I'll wait for a review on this one. An alternative, more conservative, patch might be to hack configure.ac to declare vbox and cygwin as incompatible. src/vbox/vbox_XPCOMCGlue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/vbox/vbox_XPCOMCGlue.c b/src/vbox/vbox_XPCOMCGlue.c index 9719014..9cc41b0 100644 --- a/src/vbox/vbox_XPCOMCGlue.c +++ b/src/vbox/vbox_XPCOMCGlue.c @@ -3,6 +3,7 @@ */ /* + * Copyright (C) 2013 Red Hat, Inc. * Copyright (C) 2008-2009 Sun Microsystems, Inc. * * This file is part of a free software library; you can redistribute @@ -54,7 +55,7 @@ # define DYNLIB_NAME "VBoxXPCOMC.so" #elif defined(__APPLE__) # define DYNLIB_NAME "VBoxXPCOMC.dylib" -#elif defined(_MSC_VER) || defined(__OS2__) +#elif defined(_MSC_VER) || defined(__OS2__) || defined(__CYGWIN__) # define DYNLIB_NAME "VBoxXPCOMC.dll" #else # error "Port me"