I have now installed a fresh cygwin install on a new Win32 computer, and ran into the same "cannot find binary" issue upon a fresh checkout and compile of lyx.
The following patch fixes this by ensuring that BOOST_POSIX is set for Cygwin in the src/config.h file. I see no reason why we just should not assume BOOST_POSIX for Cygwin. Index: configure.ac =================================================================== RCS file: /cvs/lyx/lyx-devel/configure.ac,v retrieving revision 1.43 diff -u -r1.43 configure.ac --- configure.ac 2005/02/04 09:19:54 1.43 +++ configure.ac 2005/02/07 00:08:34 @@ -144,6 +144,10 @@ ### Check for some Cygwin-specific details. CHECK_WITH_CYGWIN +if test "x$BOOST_POSIX" = xyes ; then + AC_DEFINE(BOOST_POSIX, 1, + [Define this to have compiled BOOST use posix pathnames internally.]) +fi ### Check for X libraries AC_PATH_XTRA Index: config/cygwin.m4 =================================================================== RCS file: /cvs/lyx/lyx-devel/config/cygwin.m4,v retrieving revision 1.2 diff -u -r1.2 cygwin.m4 --- config/cygwin.m4 2004/05/25 14:42:08 1.2 +++ config/cygwin.m4 2005/02/07 00:08:34 @@ -46,6 +46,8 @@ if test x"$WIN32_LD_EXPORT_ALL_SYMBOLS" != x; then LDFLAGS="$LDFLAGS $WIN32_LD_EXPORT_ALL_SYMBOLS" fi + + BOOST_POSIX=yes; ;; esac ]) -- Kayvan A. Sylvan | Proud husband of | Father to my kids: Sylvan Associates, Inc. | Laura Isabella Sylvan | Katherine Yelena (8/8/89) http://sylvan.com/~kayvan | "crown of her husband" | Robin Gregory (2/28/92)