Why can't my application locate cygncurses5.dll? or cygintl.dll? or cygreadline5.dll? or ...? If you upgraded recently, and suddenly vim (or some other Cygwin application) cannot find cygncurses5.dll, it probably means that you did not follow these instructions properly: http://cygwin.com/ml/cygwin-announce/2001/msg00124.html. To repair the damage, you must run Cygwin Setup again, and re-install the libncurses5 package. Note that Cygwin Setup won't show this option by default. In the ``Select packages to install'' dialog, click on the Full/Part button. This lists all packages, even those that are already installed. Scroll down to locate the libncurses5 package. Click on the ``cycle'' glyph until it says ``Reinstall''. Continue with the installation. Similarly, if something cannot find cygintl.dll, then run Cygwin Setup and re-install the libintl and libintl1 packages. For a detailed explanation of the general problem, and how to extend it to other missing DLLs (like cygreadline5.dll) and identify their containing packages, see http://cygwin.com/ml/cygwin/2002-01/msg01619.html. Why is Cygwin suddenly so slow? If you recently upgraded and suddenly every command takes a very long time, then something is probably attempting to access a network share. You may have the obsolete //c notation in your PATH or startup files. This now means the network share c, which will slow things down tremendously if it does not exist. Using //c (for C:) doesn't work anymore. (Similarly for any drive letter, e.g. //z for Z:) This ``feature'' has long been deprecated, and no longer works at all in the latest release. As of release 1.3.3, //c now means the network share c. For a detailed discussion of why this change was made, and how deal with it now, refer to http://sources.redhat.com/ml/cygwin/2001-09/msg00014.html. Why don't my services work? Most Windows services run as a special user called SYSTEM. If you installed Cygwin for "Just Me", the SYSTEM user won't see your Cygwin mount table. You need to re-mount all of your mounts as "system" for services to work. You can re-run setup.exe and select "Install for All Users", or this script will do the trick: eval "`mount -m | sed -e 's/ -u / -s /g' -e 's/$/;/'`" Why can't my services access network shares? When a service switches to a certain user, it is running as SYSTEM impersonating the user account. During impersonation, the user's password is not available and so non-public network shares are not available. For more information, see . Workarounds include using public network share that does not require authentication (for non-critical files), providing your password to a net use command, or running the service as your own user with cygrunsrv -u (see /usr/share/doc/Cygwin/cygrunsrv.README for more information). How should I set my PATH? This is done for you in the file /etc/profile, which is sourced by bash when you start it from the Desktop or Start Menu shortcut, created by setup.exe. The line is PATH="/usr/local/bin:/usr/bin:/bin:$PATH" Effectively, this prepends /usr/local/bin and /usr/bin to your Windows system path. If you choose to reset your PATH, say in $HOME/.bashrc, or by editing etc/profile directly, then you should follow this rule. You must have /usr/bin in your PATH before any Windows system directories. (And you must not omit the Windows system directories!) Otherwise you will likely encounter all sorts of problems running Cygwin applications. Bash says "command not found", but it's right there! If you compile a program, you might find that you can't run it: bash$ gcc -o hello hello.c bash$ hello bash: hello: command not found Unlike Windows, bash does not look for programs in . (the current directory) by default. You can add . to your PATH (see above), but this is not recommended (at least on UNIX) for security reasons. Just tell bash where to find it, when you type it on the command line: bash$ gcc -o hello hello.c bash$ ./hello Hello World! How do I convert between Windows and UNIX paths? Use the 'cygpath' utility. Type 'cygpath --help' for information. For example (on my installation): bash$ cygpath --windows ~/.bashrc D:\starksb\.bashrc bash$ cygpath --unix C:/cygwin/bin/cygwin.bat /usr/bin/cygwin.bat bash$ cygpath --unix C:\\cygwin\\bin\\cygwin.bat /usr/bin/cygwin.bat Note that bash interprets the backslash '\' as an escape character, so you must type it twice in the bash shell if you want it to be recognized as such. Why doesn't bash read my .bashrc file on startup? Your .bashrc is read from your home directory specified by the HOME environment variable. It uses /.bashrc if HOME is not set. So you need to set HOME correctly, or move your .bashrc to the top of the drive mounted as / in Cygwin. How can I get bash filename completion to be case insensitive? Add the following to your ~/.bashrc file: shopt -s nocaseglob and add the following to your ~/.inputrc file: set completion-ignore-case on Can I use paths/filenames containing spaces in them? Cygwin does support spaces in filenames and paths. That said, some utilities that use the library may not, since files don't typically contain spaces in Unix. If you stumble into problems with this, you will need to either fix the utilities or stop using spaces in filenames used by Cygwin tools. In particular, bash interprets space as a word separator. You would have to quote a filename containing spaces, or escape the space character. For example: bash-2.03$ cd '/cygdrive/c/Program Files' or bash-2.03$ cd /cygdrive/c/Program\ Files Why can't I cd into a shortcut to a directory? Cygwin versions < 1.3.0 do not follow MS Windows Explorer Shortcuts (*.lnk files). It sees a shortcut as a regular file and this you cannot "cd" into it. Since version 1.3.0, Cygwin uses shortcuts as symlinks by default. Cygwin shortcuts are different from shortcuts created by native Windows applications. Windows applications can usually make use of Cygwin shortcuts but not vice versa. This is by choice. The reason is that Windows shortcuts may contain a bunch of extra information which would get lost, if, for example, Cygwin tar archives and extracts them as symlinks. Changing a Cygwin shortcut in Windows Explorer usually changes a Cygwin shortcut into a Windows native shortcut. Afterwards, Cygwin will not recognize it as symlink anymore. I'm having basic problems with find. Why? Make sure you are using the find that came with Cygwin and that you aren't picking up the Win32 find command instead. You can verify that you are getting the right one by doing a "type find" in bash. If the path argument to find, including current directory (default), is itself a symbolic link, then find will not traverse it unless you specify the -follow option. This behavior is different than most other UNIX implementations, but is not likely to change. If find does not seem to be producing enough results, or seems to be missing out some directories, you may be experiencing a problem with one of find's optimisations. The absence of . and .. directories on some filesystems, such as DVD-R UDF, can confuse find. See the documentation for the option -noleaf in the man page. Why doesn't su work? The su command has been in and out of Cygwin distributions, but it has not been ported to Cygwin and has never worked. It is currently installed as part of the sh-utils, but again, it does not work. You may be able to use login instead, but you should read http://www.cygwin.com/ml/cygwin/2001-03/msg00337.html first. For some technical background into why su doesn't work, read http://www.cygwin.com/ml/cygwin/2003-06/msg00897.html and related messages. Why doesn't man (or apropos) work? Before you can use man -k or apropos, you must create the whatis database. Just run the command /usr/sbin/makewhatis (it may take a minute to complete). Why doesn't chmod work? ntsec will allow UNIX permissions in Windows NT on NTFS file systems. This is on by default (a recent change). ntea works on NTFS and FAT but it creates a huge, undeletable file on FAT filesystems. (The ntsec and ntea settings are values for the CYGWIN environment variable. See the Cygwin User's Guide at http://cygwin.com/cygwin-ug-net/cygwin-ug-net.html for more information on this variable and its settings.) There is no solution at all for Windows 9x. If you have an application that requires a certain permission mode on a file, you may be able to work around this requirement by modifying the application's source code. For a hint, based on work done by Corinna Vinschen for OpenSSH, see this message from the cygwin mailing list: http://cygwin.com/ml/cygwin/2000-11/msg01176.html. Why doesn't mkdir -p work on a network share? Starting with coreutils-5.3.0-6 and cygwin-1.5.17, you can do something like this: bash$ mkdir -p //MACHINE/Share/path/to/new/dir However, coreutils expects Unix path names, so something like mkdir -p \\\\machine\\share\\path will fail. Why doesn't my shell script work? There are two basic problems you might run into. One is the fact that /bin/sh is really bash (prior to bash-3.0-6, /bin/sh was ash). and is missing some features you might expect in /bin/sh, particularly if you are used to /bin/sh actually being zsh (MacOS X "Panther") or ksh (Tru64). Or, it could be a permission problem, and Cygwin doesn't understand that your script is executable. Because chmod may not work (see FAQ entry above), Cygwin must read the contents of files to determine if they are executable. If your script does not start with #! /bin/sh (or any path to a script interpreter, it does not have to be /bin/sh) then Cygwin will not know it is an executable script. The Bourne shell idiom : # This is the 2nd line, assume processing by /bin/sh also works. Note that you can use mount -x to force Cygwin to treat all files under the mount point as executable. This can be used for individual files as well as directories. Then Cygwin will not bother to read files to determine whether they are executable. How do I print under Cygwin? There is no working lp or lpr system as you would find on UNIX. Jason Tishler has written a couple of messages that explain how to use a2ps (for nicely formatted text in PostScript) and ghostscript (to print PostScript files on non-PostScript Windows printers). Start at http://cygwin.com/ml/cygwin/2001-04/msg00657.html. Note that the file command is now available as part of Cygwin setup. Alternatively, on NT, you can use the Windows print command. (It does not seem to be available on Win9x.) Type bash$ print /\? for usage instructions (note the ? must be escaped from the shell). Finally, you can simply cat the file to the printer's share name: bash$ cat myfile > //host/printer You may need to press the formfeed button on your printer or append the formfeed character to your file. Why don't international (Unicode) characters work? Internationalization is a complex issue. The short answer is that Cygwin is not Unicode-aware, so things that might work in Linux will not necessarily work on Cygwin. However, some things do work. To type international characters (£äö) in bash, add the following lines to your ~/.inputrc file and restart bash: set meta-flag on set convert-meta off set output-meta on set input-meta on set kanji-code sjis set meta-flag on These are options to the readline library, which you can read about in the bash(1) and readline(3) man pages. Other tools that do not use readline for display, such as less and ls, require additional settings, which could be put in your ~/.bashrc: alias less='/bin/less -r' alias ls='/bin/ls -F --color=tty --show-control-chars' export LANG="ja_JP.SJIS" export OUTPUT_CHARSET="sjis" These examples use the Japanese Shift-JIS character set, obviously you will want to change them for your own locale. Why don't cursor keys work under Win95/Win98? (Please note: This section has not yet been updated for the latest net release.) Careful examination shows that they not just non-functional, but rather behave strangely, for example, with NumLock off, keys on numeric keyboard work, until you press usual cursor keys, when even numeric stop working, but they start working again after hitting alphanumeric key, etc. This reported to happen on localized versions of Win98 and Win95, and not specific to Cygwin; there are known cases of Alt+Enter (fullscreen/windowed toggle) not working and shifts sticking with other programs. The cause of this problem is Microsoft keyboard localizer which by default installed in 'autoexec.bat'. Corresponding line looks like: keyb ru,,C:\WINDOWS\COMMAND\keybrd3.sys (That's for russian locale.) You should comment that line if you want your keys working properly. Of course, this will deprive you of your local alphabet keyboard support, so you should think about another localizer. ex-USSR users are of course knowledgeable of Keyrus localizer, and it might work for other locales too, since it has keyboard layout editor. But it has russian messages and documentation ;-( Reference URL is http://www.hnet.ru/software/contrib/Utils/KeyRus/ (note the you may need to turn off Windows logo for Keyrus to operate properly). Is it OK to have multiple copies of the DLL? You should only have one copy of the Cygwin DLL on your system. If you have multiple versions, they will conflict and cause problems. If you get the error "shared region is corrupted" or "shared region version mismatch" it means you have multiple versions of cygwin1.dll running at the same time. This could happen, for example, if you update cygwin1.dll without exiting all Cygwin apps (including inetd) beforehand. The only DLL that is sanctioned by the Cygwin project is the one that you get by running http://cygwin.com/setup.exe, installed in the directory controlled by this program. If you have other versions on your system and desire help from the cygwin project, you should delete or rename all DLLs that are not installed by setup.exe. If you're trying to find multiple versions of the DLL that are causing this problem, reboot first, in case DLLs still loaded in memory are the cause. Then use the Windows System find utility to search your whole machine, not just components in your PATH (as 'type' would do) or cygwin-mounted filesystems (as Cygwin 'find' would do). Why isn't package XYZ available in Cygwin? Probably because there is nobody willing or able to maintain it. It takes time, and the priority for the Cygwin Team is the Cygwin package. The rest is a volunteer effort. Want to contribute? See http://cygwin.com/setup.html. Why is the Cygwin package of XYZ so out of date? (Also: Why is the version of package XYZ older than the version that I can download from the XYZ web site? Why is the version of package XYZ older than the version that I installed on my linux system? Is there something special about Cygwin which requires that only an older version of package XYZ will work on it?) Every package in the Cygwin distribution has a maintainer who is responsible for sending out updates of the package. This person is a volunteer who is rarely the same person as the official developer of the package. If you notice that a version of a package seems to be out of date, the reason is usually pretty simple -- the person who is maintaining the package hasn't gotten around to updating it yet. Rarely, the newer package actually requires complex changes that the maintainer is working out. If you urgently need an update, sending a polite message to the cygwin mailing list pinging the maintainer is perfectly acceptable. There are no guarantees that the maintainer will have time to update the package or that you'll receive a response to your request, however. Remeber that the operative term here is "volunteer". How can I access other drives? You have some flexibility here. Cygwin has a builtin "cygdrive prefix" for drives that are not mounted. You can access any drive, say Z:, as '/cygdrive/z/'. In some applications (notably bash), you can use the familiar windows <drive>:/path/, using posix forward-slashes ('/') instead of Windows backward-slashes ('\'). (But see the warning below!) This maps in the obvious way to the Windows path, but will be converted internally to use the Cygwin path, following mounts (default or explicit). For example: bash$ cd C:/Windows bash$ pwd /cygdrive/c/Windows and bash$ cd C:/cygwin bash$ pwd / for a default setup. You could also use backward-slashes in the Windows path, but these would have to be escaped from the shell. Warning: There is some ambiguity in going from a Windows path to the posix path, because different posix paths, through different mount points, could map to the same Windows directory. This matters because different mount points may be binmode or textmode, so the behavior of Cygwin apps will vary depending on the posix path used to get there. You can avoid the ambiguity of Windows paths, and avoid typing "/cygdrive", by explicitly mounting drives to posix paths. For example: bash$ mkdir /c bash$ mount c:/ /c bash$ ls /c Then /cygdrive/c/Windows becomes /c/Windows which is a little less typing. Note that you only need to mount drives once. The mapping is kept in the registry so mounts stay valid pretty much indefinitely. You can only get rid of them with umount, or the registry editor. The '-b' option to mount mounts the mountpoint in binary mode ("binmode") where text and binary files are treated equivalently. This should only be necessary for badly ported Unix programs where binary flags are missing from open calls. It is also the setting for /, /usr/bin and /usr/lib in a default Cygwin installation. The default for new mounts is text mode ("textmode"), which is also the mode for all "cygdrive" mounts. You can change the default cygdrive prefix and whether it is binmode or textmode using the mount command. For example, bash$ mount -b --change-cygdrive-prefix cygdrive will change all /cygdrive/... mounts to binmode. How can I copy and paste into Cygwin console windows? First, consider using rxvt instead of the standard console window. In rxvt, selecting with the left-mouse also copies, and middle-mouse pastes. It couldn't be easier! Under Windows NT, open the properties dialog of the console window. The options contain a toggle button, named "Quick edit mode". It must be ON. Save the properties. Under Windows 9x, open the properties dialog of the console window. Select the Misc tab. Uncheck Fast Pasting. Check QuickEdit. You can also bind the insert key to paste from the clipboard by adding the following line to your .inputrc file: "\e[2~": paste-from-clipboard What firewall should I use with Cygwin? We have had good reports about Kerio Personal Firewall, ZoneLabs Integrity Desktop, and the built-in firewall in Windows XP. Other well-known products including ZoneAlarm and Norton Internet Security have caused problems for some users but work fine for others. At last report, Agnitum Outpost did not work with Cygwin. If you are having strange connection-related problems, disabling the firewall is a good troubleshooting step (as is closing or disabling all other running applications, especially resource-intensive processes such as indexed search). On the whole, Cygwin doesn't care which firewall is used. The few rare exceptions have to do with socket code. Cygwin uses sockets to implement many of its functions, such as IPC. Some overzealous firewalls install themselves deeply into the winsock stack (with the 'layered service provider' API) and install hooks throughout. Sadly the mailing list archives are littered with examples of poorly written firewall-type software that causes things to break. Note that with many of these products, simply disabling the firewall does not remove these changes; it must be completely uninstalled. How can I share files between Unix and Windows? During development, we have both Linux boxes running Samba and Windows machines. We often build with cross-compilers under Linux and copy binaries and source to the Windows system or just toy with them directly off the Samba-mounted partition. On dual-boot NT/Windows 9x machines, we usually use the FAT filesystem so we can also access the files under Windows 9x. Is Cygwin case-sensitive? What are managed mounts? Several Unix programs expect to be able to use to filenames spelled the same way, but with different case. A prime example of this is perl's configuration script, which wants Makefile and makefile. WIN32 can't tell the difference between files with just different case, so the configuration fails. To help with this problem, starting in cygwin-1.5.0 it is possible to have a case sensitive Cygwin managed mount. This is an experimental feature and should be used with caution. You should only use it for directories that are initially unpopulated and are due to be completely managed by cygwin (hence the name). So, the best use would be to create an empty directory, mount it, and then add files to it: mkdir /managed-dir mount -o managed c:/cygwin/managed-dir /managed-dir cd /managed-dir/ touch makefile touch Makefile What about DOS special filenames? Files cannot be named com1, lpt1, or aux (to name a few); either as the root filename or as the extension part. If you do, you'll have trouble. Unix programs don't avoid these names which can make things interesting. E.g., the perl distribution has a file called aux.sh. The perl configuration tries to make sure that aux.sh is there, but an operation on a file with the magic letters 'aux' in it will hang. When it hangs, how do I get it back? If something goes wrong and the tools hang on you for some reason (easy to do if you try and read a file called aux.sh), first try hitting ^C to return to bash or the cmd prompt. If you start up another shell, and applications don't run, it's a good bet that the hung process is still running somewhere. Use the Task Manager, pview, or a similar utility to kill the process. And, if all else fails, there's always the reset button/power switch. This should never be necessary under Windows NT. Why the weird directory structure? Why do /lib and /usr/lib (and /bin, /usr/bin) point to the same thing? Why use mounts instead of symbolic links? Can I use a disk root (e.g., C:\) as Cygwin root? Why is this discouraged? After a new installation in the default location, your mount points will look something like this: bash$ mount C:\cygwin\bin on /usr/bin type system (binmode) C:\cygwin\lib on /usr/lib type system (binmode) C:\cygwin on / type system (binmode) (Exactly what you see depends on what options you gave to setup.exe.) Note that /bin and /usr/bin point to the same location, as do /lib and /usr/lib. This is intentional, and you should not undo these mounts unless you really know what you are doing. Various applications and packages may expect to be installed in /lib or /usr/lib (similarly /bin or /usr/bin). Rather than distinguish between them and try to keep track of them (possibly requiring the occasional duplication or symbolic link), it was decided to maintain only one actual directory, with equivalent ways to access it. Symbolic links had been considered for this purpose, but were dismissed because they do not always work on Samba drives. Also, mounts are faster to process because no disk access is required to resolve them. Note that non-cygwin applications will not observe Cygwin mounts (or symlinks for that matter). For example, if you use WinZip to unpack the tar distribution of a Cygwin package, it may not get installed to the correct Cygwin path. So don't do this! It is strongly recommended not to make the Cygwin root directory the same as your drive's root directory, unless you know what you are doing and are prepared to deal with the consequences. It is generally easier to maintain the Cygwin hierarchy if it is isolated from, say, C:\. For one thing, you avoid possible collisions with other (non-cygwin) applications that may create (for example) \bin and \lib directories. (Maybe you have nothing like that installed now, but who knows about things you might add in the future?) How do anti-virus programs like Cygwin? Users have reported that NAI (formerly McAfee) VirusScan for NT (and others?) is incompatible with Cygwin. This is because it tries to scan the newly loaded shared memory in cygwin1.dll, which can cause fork() to fail, wreaking havoc on many of the tools. (It is not confirmed that this is still a problem, however.) There have been several reports of NAI VirusScan causing the system to hang when unpacking tar.gz archives. This is surely a bug in VirusScan, and should be reported to NAI. The only workaround is to disable VirusScan when accessing these files. This can be an issue during setup, and is discussed in that FAQ entry. Some users report a significant performance hit using Cygwin when their anti-virus software is enabled. Rather than disable the anti-virus software completely, it may be possible to specify directories whose contents are exempt from scanning. In a default installation, this would be C:\cygwin\bin. Obviously, this could be exploited by a hostile non-Cygwin program, so do this at your own risk. Is there a Cygwin port of GNU Emacs? Yes! It uses the X11 (http://cygwin.com/xfree/) Windows interface. From a remote login shell, this ``emacs -nw'' works fine. There is also a non-X11 version which just provides the text-only terminal interface. Use Cygwin Setup to install either one (or both). What about NT Emacs? If you want GNU Emacs with a native Microsoft Windows interface, but without X, then you must use the native Windows port, commonly known as ``NT Emacs''. You get NT Emacs from any GNU mirror. It is not available from Cygwin Setup. NT Emacs uses the Windows command shell by default. Since it is not a Cygwin application, it has no knowledge of Cygwin mounts. With those points in mind, you need to add the following code to your ~/.emacs (or ~/_emacs) file in order to use Cygwin bash. This is particularly useful for the JDEE package (http://jdee.sunsite.dk/). The following settings are for Emacs 21.1: ;; This assumes that Cygwin is installed in C:\cygwin (the ;; default) and that C:\cygwin\bin is not already in your ;; Windows Path (it generally should not be). ;; (setq exec-path (cons "C:/cygwin/bin" exec-path)) (setenv "PATH" (concat "C:\\cygwin\\bin;" (getenv "PATH"))) ;; ;; NT-emacs assumes a Windows command shell, which you change ;; here. ;; (setq shell-file-name "bash") (setenv "SHELL" shell-file-name) (setq explicit-shell-file-name shell-file-name) ;; ;; This removes unsightly ^M characters that would otherwise ;; appear in the output of java applications. ;; (add-hook 'comint-output-filter-functions 'comint-strip-ctrl-m) If you want NT Emacs to understand Cygwin paths, get cygwin-mount.el from http://www.emacswiki.org/elisp/index.html. Note that all of this ``just works'' if you use the Cygwin port of Emacs from Cygwin Setup. What about XEmacs? For a concise description of the current situation with XEmacs, see this message from the Cygwin mailing list: http://cygwin.com/ml/cygwin/2002-11/msg00609.html. Is there a better alternative to the standard console window? Yes! Use rxvt instead. It's an optional package in Cygwin Setup. You can use it with or without X11. You can resize it easily by dragging an edge or corner. Copy and paste is easy with the left and middle mouse buttons, respectively. It will honor settings in your ~/.Xdefaults file, even without X. Don't invoke as simply ``rxvt'' because that will run /bin/sh (really ash) which is not a good interactive shell. For details see /usr/doc/Cygwin/rxvt-<ver>.README. info error "dir: No such file or directory" Cygwin packages install their info documentation in the /usr/share/info directory. But you need to create a dir file there before the standalone info program (probably /usr/bin/info) can be used to read those info files. This is how you do it: bash$ cd /usr/share/info bash$ for f in *.info ; do install-info $f dir ; done This may generate warnings: install-info: warning: no info dir entry in `gzip.info' install-info: warning: no info dir entry in `time.info' The install-info command cannot parse these files, so you will have to add their entries to /usr/share/info/dir by hand. Even if the dir file already exists, you may have to update it when you install new Cygwin packages. Some packages update the dir file for you, but many don't. Why do I get a message saying Out of Queue slots? "Out of queue slots!" generally occurs when you're trying to remove many files that you do not have permission to remove (either because you don't have permission, they are opened exclusively, etc). What happens is Cygwin queues up these files with the supposition that it will be possible to delete these files in the future. Assuming that the permission of an affected file does change later on, the file will be deleted as requested. However, if too many requests come in to delete inaccessible files, the queue overflows and you get the message you're asking about. Usually you can remedy this with a quick chmod, close of a file, or other such thing. (Thanks to Larry Hall for this explanation). Why don't symlinks work on samba-mounted filesystems? Symlinks are marked with "system" file attribute. Samba does not enable this attribute by default. To enable it, consult your Samba documentation and then add these lines to your samba configuration file: map system = yes create mask = 0775 Note that the 0775 can be anything as long as the 0010 bit is set. Why does df report sizes incorrectly. There is a bug in the Win32 API function GetFreeDiskSpace that makes it return incorrect values for disks larger than 2 GB in size. Perhaps that may be your problem? Why doesn't Cygwin tcl/tk understand Cygwin paths? The versions of Tcl/Tk distributed with Cygwin (e.g. cygtclsh80.exe, cygwish80.exe) are not actually "Cygwin versions" of those tools. They are built with the -mno-cygwin option to gcc, which means they do not understand Cygwin mounts or symbolic links. See the entry "How do I convert between Windows and UNIX paths?" elsewhere in this FAQ.