This file describes various problems that have been encountered in compiling, installing and running GNU Emacs. * You configure Emacs to use a directory such as /usr/local/sun3.lib/emacs and the directory name gets mangled in the process of building Emacs. This is because building Emacs involves passing a makefile through the C preprocessor. The directory names that you specified go through that process, and if they happen to use any predefined macro names, those macro names get substituted. For example, if you are on a Sun 3, the name `sun3' is a predefined macro. This is an Emacs bug, and will be fixed; but it was too risky to fix for 19.21. For now, you must use different names for those directories (perhaps via symbolic links). * You "lose characters" after typing Compose Character key. This is because the Compose Character key is defined as the keysym Multi_key, and Emacs (seeing that) does the proper X11 character-composition processing. If you don't want your Compose key to do that, you can redefine it with xmodmap. For example, here's one way to turn it into a Meta key: xmodmap -e "keysym Multi_key = Meta_L" If all users at your site of a particular keyboard prefer Meta to Compose, you can make the remapping happen automatically by adding the xmodmap command to the xdm setup script for that display. * Watch out for .emacs files and EMACSLOADPATH environment vars These control the actions of Emacs. ~/.emacs is your Emacs init file. EMACSLOADPATH overrides which directories the function "load" will search. If you observe strange problems, check for these and get rid of them, then try again. * After running emacs once, subsequent invocations crash. Some versions of SVR4 have a serious bug in the implementation of the mmap () system call in the kernel; this causes emacs to run correctly the first time, and then crash when run a second time. Contact your vendor and ask for the mmap bug fix; in the mean time, you may be able to work around the problem by adding a line to your operating system description file (whose name is reported by the configure script) that reads: #define SYSTEM_MALLOC This makes Emacs use memory less efficiently, but seems to work around the kernel bug. * Inability to send an Alt-modified key, when Emacs is communicating directly with an X server. If you have tried to bind an Alt-modified key as a command, and it does not work to type the command, the first thing you should check is whether the key is getting through to Emacs. To do this, type C-h c followed by the Alt-modified key. C-h c should say what kind of event it read. If it says it read an Alt-modified key, then make sure you have made the key binding correctly. If C-h c reports an event that doesn't have the Alt modifier, it may be because your X server has no key for the Alt modifier. The X server that comes from MIT does not set up the Alt modifier by default. If your keyboard has keys named Alt, you can enable them as follows: xmodmap -e 'add mod2 = Alt_L' xmodmap -e 'add mod2 = Alt_R' If the keyboard has just one key named Alt, then only one of those commands is needed. The modifier `mod2' is a reasonable choice if you are using an unmodified MIT version of X. Otherwise, choose any modifier bit not otherwise used. If your keyboard does not have keys named Alt, you can use some other keys. Use the keysym command in xmodmap to turn a function key (or some other 'spare' key) into Alt_L or into Alt_R, and then use the commands show above to make them modifier keys. Note that if you have Alt keys but no Meta keys, Emacs translates Alt into Meta. This is because of the great importance of Meta in Emacs. * `Pid xxx killed due to text modification or page I/O error' On HP/UX, you can get that error when the Emacs executable is on an NFS file system. HP/UX responds this way if it tries to swap in a page and does not get a response from the server within a timeout whose default value is just ten seconds. If this happens to you, extend the timeout period. * `expand-file-name' fails to work on any but the machine you dumped Emacs on. On Ultrix, if you use any of the functions which look up information in the passwd database before dumping Emacs (say, by using expand-file-name in site-init.el), then those functions will not work in the dumped Emacs on any host but the one Emacs was dumped on. The solution? Don't use expand-file-name in site-init.el, or in anything it loads. Yuck - some solution. I'm not sure why this happens; if you can find out exactly what is going on, and perhaps find a fix or a workaround, please let us know. Perhaps the YP functions cache some information, the cache is included in the dumped Emacs, and is then inaccurate on any other host. * On some variants of SVR4, Emacs does not work at all with X. Try defining BROKEN_FIONREAD in your config.h file. If this solves the problem, please send a bug report to tell us this is needed; be sure to say exactly what type of machine and system you are using. * Linking says that the functions insque and remque are undefined. Change oldXMenu/Makefile by adding insque.o to the variable OBJS. * Emacs fails to understand most Internet host names, even though the names work properly with other programs on the same system. * Emacs won't work with X-windows if the value of DISPLAY is HOSTNAME:0. * GNUs can't make contact with the specified host for nntp. This typically happens on Suns and other systems that use shared libraries. The cause is that the site has installed a version of the shared library which uses a name server--but has not installed a similar version of the unshared library which Emacs uses. The result is that most programs, using the shared library, work with the nameserver, but Emacs does not. The fix is to install an unshared library that corresponds to what you installed in the shared library, and then relink Emacs. On SunOS 4.1, simply define HAVE_RES_INIT. If you have already installed the name resolver in the file libresolv.a, then you need to compile Emacs to use that library. The easiest way to do this is to add to config.h a definition of LIBS_SYSTEM, LIBS_MACHINE or LIB_STANDARD which uses -lresolv. Watch out! If you redefine a macro that is already in use in your configuration to supply some other libraries, be careful not to lose the others. Thus, you could start by adding this to config.h: #define LIBS_SYSTEM -lresolv Then if this gives you an error for redefining a macro, and you see that the s- file defines LIBS_SYSTEM as -lfoo -lbar, you could change config.h again to say this: #define LIBS_SYSTEM -lresolv -lfoo -lbar * On a Sun running SunOS 4.1.1, you get this error message from GNU ld: /lib/libc.a(_Q_sub.o): Undefined symbol __Q_get_rp_rd referenced from text segment The problem is in the Sun shared C library, not in GNU ld. The solution is to install Patch-ID# 100267-03 from Sun. * Self documentation messages are garbled. This means that the file `etc/DOC-...' doesn't properly correspond with the Emacs executable. Redumping Emacs and then installing the corresponding pair of files should fix the problem. * Trouble using ptys on AIX. People often install the pty devices on AIX incorrectly. Use `smit pty' to reinstall them properly. * Shell mode on HP/UX gives the message, "`tty`: Ambiguous". christos@theory.tn.cornell.edu says: The problem is that in your .cshrc you have something that tries to execute `tty`. If you are not running the shell on a real tty then tty will print "not a tty". Csh expects one word in some places, but tty is giving it back 3. The solution is to add a pair of quotes around `tty` to make it a single word: if (`tty` == "/dev/console") should be changed to: if ("`tty`" == "/dev/console") Even better, move things that set up terminal sections out of .cshrc and into .login. * Using X Windows, control-shift-leftbutton makes Emacs hang. Use the shell command `xset bc' to make the old X Menu package work. * Emacs running under X Windows does not handle mouse clicks. * `emacs -geometry 80x20' finds a file named `80x20'. One cause of such problems is having (setq term-file-prefix nil) in your .emacs file. Another cause is a bad value of EMACSLOADPATH in the environment. * Emacs gets error message from linker on Sun. If the error message says that a symbol such as `f68881_used' or `ffpa_used' or `start_float' is undefined, this probably indicates that you have compiled some libraries, such as the X libraries, with a floating point option other than the default. It's not terribly hard to make this work with small changes in crt0.c together with linking with Fcrt1.o, Wcrt1.o or Mcrt1.o. However, the easiest approach is to build Xlib with the default floating point option: -fsoft. * Emacs fails to get default settings from X Windows server. The X library in X11R4 has a bug; it interchanges the 2nd and 3rd arguments to XGetDefaults. Define the macro XBACKWARDS in config.h to tell Emacs to compensate for this. I don't believe there is any way Emacs can determine for itself whether this problem is present on a given system. * Keyboard input gets confused after a beep when using a DECserver as a concentrator. This problem seems to be a matter of configuring the DECserver to use 7 bit characters rather than 8 bit characters. * M-x shell persistently reports "Process shell exited abnormally with code 1". This happened on Suns as a result of what is said to be a bug in Sunos version 4.0.x. The only fix was to reboot the machine. * Programs running under terminal emulator do not recognize `emacs' terminal type. The cause of this is a shell startup file that sets the TERMCAP environment variable. The terminal emulator uses that variable to provide the information on the special terminal type that Emacs emulates. Rewrite your shell startup file so that it does not change TERMCAP in such a case. You could use the following conditional which sets it only if it is undefined. if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-file Or you could set TERMCAP only when you set TERM--which should not happen in a non-login shell. * X Windows doesn't work if DISPLAY uses a hostname. People have reported kernel bugs in certain systems that cause Emacs not to work with X Windows if DISPLAY is set using a host name. But the problem does not occur if DISPLAY is set to `unix:0.0'. I think the bug has to do with SIGIO or FIONREAD. You may be able to compensate for the bug by doing (set-input-mode nil nil). However, that has the disadvantage of turning off interrupts, so that you are unable to quit out of a Lisp program by typing C-g. The easy way to do this is to put (setq x-sigio-bug t) in your site-init.el file. * Problem with remote X server on Suns. On a Sun, running Emacs on one machine with the X server on another may not work if you have used the unshared system libraries. This is because the unshared libraries fail to use YP for host name lookup. As a result, the host name you specify may not be recognized. * Shell mode ignores interrupts on Apollo Domain You may find that M-x shell prints the following message: Warning: no access to tty; thus no job control in this shell... This can happen if there are not enough ptys on your system. Here is how to make more of them. % cd /dev % ls pty* # shows how many pty's you have. I had 8, named pty0 to pty7) % /etc/crpty 8 # creates eight new pty's * Fatal signal in the command temacs -l loadup inc dump This command is the final stage of building Emacs. It is run by the Makefile in the src subdirectory, or by build.com on VMS. It has been known to get fatal errors due to insufficient swapping space available on the machine. On 68000's, it has also happened because of bugs in the subroutine `alloca'. Verify that `alloca' works right, even for large blocks (many pages). * test-distrib says that the distribution has been clobbered * or, temacs prints "Command key out of range 0-127" * or, temacs runs and dumps xemacs, but xemacs totally fails to work. * or, temacs gets errors dumping xemacs This can be because the .elc files have been garbled. Do not be fooled by the fact that most of a .elc file is text: these are binary files and can contain all 256 byte values. In particular `shar' cannot be used for transmitting GNU Emacs. It typically truncates "lines". What appear to be "lines" in a binary file can of course be of any length. Even once `shar' itself is made to work correctly, `sh' discards null characters when unpacking the shell archive. I have also seen character \177 changed into \377. I do not know what transfer means caused this problem. Various network file transfer programs are suspected of clobbering the high bit. If you have a copy of Emacs that has been damaged in its nonprinting characters, you can fix them: 1) Record the names of all the .elc files. 2) Delete all the .elc files. 3) Recompile alloc.c with a value of PURESIZE twice as large. You might as well save the old alloc.o. 4) Remake xemacs. It should work now. 5) Running xemacs, do Meta-x byte-compile-file repeatedly to recreate all the .elc files that used to exist. You may need to increase the value of the variable max-lisp-eval-depth to succeed in running the compiler interpreted on certain .el files. 400 was sufficient as of last report. 6) Reinstall the old alloc.o (undoing changes to alloc.c if any) and remake temacs. 7) Remake xemacs. It should work now, with valid .elc files. * temacs prints "Pure Lisp storage exhausted" This means that the Lisp code loaded from the .elc and .el files during temacs -l loadup inc dump took up more space than was allocated. This could be caused by 1) adding code to the preloaded Lisp files 2) adding more preloaded files in loadup.el 3) having a site-init.el or site-load.el which loads files. Note that ANY site-init.el or site-load.el is nonstandard; if you have received Emacs from some other site and it contains a site-init.el or site-load.el file, consider deleting that file. 4) getting the wrong .el or .elc files (not from the directory you expected). 5) deleting some .elc files that are supposed to exist. This would cause the source files (.el files) to be loaded instead. They take up more room, so you lose. 6) a bug in the Emacs distribution which underestimates the space required. If the need for more space is legitimate, change the definition of PURESIZE in puresize.h. But in some of the cases listed above, this problem is a consequence of something else that is wrong. Be sure to check and fix the real problem. * Changes made to .el files do not take effect. You may have forgotten to recompile them into .elc files. Then the old .elc files will be loaded, and your changes will not be seen. To fix this, do M-x byte-recompile-directory and specify the directory that contains the Lisp files. Emacs should print a warning when loading a .elc file which is older than the corresponding .el file. * The dumped Emacs (xemacs) crashes when run, trying to write pure data. Two causes have been seen for such problems. 1) On a system where getpagesize is not a system call, it is defined as a macro. If the definition (in both unexec.c and malloc.c) is wrong, it can cause problems like this. You might be able to find the correct value in the man page for a.out (5). 2) Some systems allocate variables declared static among the initialized variables. Emacs makes all initialized variables in most of its files pure after dumping, but the variables declared static and not initialized are not supposed to be pure. On these systems you may need to add "#define static" to the m- or the s- file. * Compilation errors on VMS. You will get warnings when compiling on VMS because there are variable names longer than 32 (or whatever it is) characters. This is not an error. Ignore it. VAX C does not support #if defined(foo). Uses of this construct were removed, but some may have crept back in. They must be rewritten. There is a bug in the C compiler which fails to sign extend characters in conditional expressions. The bug is: char c = -1, d = 1; int i; i = d ? c : d; The result is i == 255; the fix is to typecast the char in the conditional expression as an (int). Known occurrences of such constructs in Emacs have been fixed. * rmail gets error getting new mail rmail gets new mail from /usr/spool/mail/$USER using a program called `movemail'. This program interlocks with /bin/mail using the protocol defined by /bin/mail. There are two different protocols in general use. One of them uses the `flock' system call. The other involves creating a lock file; `movemail' must be able to write in /usr/spool/mail in order to do this. You control which one is used by defining, or not defining, the macro MAIL_USE_FLOCK in config.h or the m- or s- file it includes. IF YOU DON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOUR SYSTEM, YOU CAN LOSE MAIL! If your system uses the lock file protocol, and fascist restrictions prevent ordinary users from writing the lock files in /usr/spool/mail, you may need to make `movemail' setgid to a suitable group such as `mail'. You can use these commands (as root): chgrp mail movemail chmod 2755 movemail * Emacs spontaneously displays "I-search: " at the bottom of the screen. This means that Control-S/Control-Q "flow control" is being used. C-s/C-q flow control is bad for Emacs editors because it takes away C-s and C-q as user commands. Since editors do not output long streams of text without user commands, there is no need for a user-issuable "stop output" command in an editor; therefore, a properly designed flow control mechanism would transmit all possible input characters without interference. Designing such a mechanism is easy, for a person with at least half a brain. There are three possible reasons why flow control could be taking place: 1) Terminal has not been told to disable flow control 2) Insufficient padding for the terminal in use 3) Some sort of terminal concentrator or line switch is responsible First of all, many terminals have a set-up mode which controls whether they generate flow control characters. This must be set to "no flow control" in order for Emacs to work. Sometimes there is an escape sequence that the computer can send to turn flow control off and on. If so, perhaps the termcap `ti' string should turn flow control off, and the `te' string should turn it on. Once the terminal has been told "no flow control", you may find it needs more padding. The amount of padding Emacs sends is controlled by the termcap entry for the terminal in use, and by the output baud rate as known by the kernel. The shell command `stty' will print your output baud rate; `stty' with suitable arguments will set it if it is wrong. Setting to a higher speed causes increased padding. If the results are wrong for the correct speed, there is probably a problem in the termcap entry. You must speak to a local Unix wizard to fix this. Perhaps you are just using the wrong terminal type. For terminals that lack a "no flow control" mode, sometimes just giving lots of padding will prevent actual generation of flow control codes. You might as well try it. If you are really unlucky, your terminal is connected to the computer through a concentrator which sends flow control to the computer, or it insists on sending flow control itself no matter how much padding you give it. You are screwed! You should replace the terminal or concentrator with a properly designed one. In the mean time, some drastic measures can make Emacs semi-work. One drastic measure to ignore C-s and C-q, while sending enough padding that the terminal will not really lose any output. To make such an adjustment, you need only invoke the function enable-flow-control-on with a list of terminal types in your own .emacs file. As arguments, give it the names of one or more terminal types you use which require flow control adjustments. Here's an example: (enable-flow-control-on "vt200" "vt300" "vt101" "vt131") If the situation is only temporary and you don't expect it to be the case the next time you use emacs (e.g. you're visiting someplace where C-s and C-q have taken over, but expect to be back to a safe part of the world in a few hours), you can just type M-x enable-flow-control at the beginning of your emacs session. An even more drastic measure is to make Emacs use flow control. To do this, evaluate the Lisp expression (set-input-mode nil t META). (The argument META should be t if you have a meta key, and nil otherwise.) Emacs will then interpret C-s and C-q as flow control commands. (More precisely, it will allow the kernel to do so as it usually does.) You will lose the ability to use them for Emacs commands. Also, as a consequence of using CBREAK mode, the terminal's Meta-key, if any, will not work, and C-g will be liable to cause a loss of output which will produce garbage on the screen. (These problems apply to 4.2BSD; they may not happen in 4.3 or VMS, and I don't know what would happen in sysV.) You can use keyboard-translate-table, as shown above, to map two other input characters (such as C-^ and C-\) into C-s and C-q, so that you can still search and quote. I have no intention of ever redesigning the Emacs command set for the assumption that terminals use C-s/C-q flow control. This flow control technique is a bad design, and terminals that need it are bad merchandise and should not be purchased. If you can get some use out of GNU Emacs on inferior terminals, I am glad, but I will not make Emacs worse for properly designed systems for the sake of inferior systems. * Control-S and Control-Q commands are ignored completely. For some reason, your system is using brain-damaged C-s/C-q flow control despite Emacs's attempts to turn it off. Perhaps your terminal is connected to the computer through a concentrator that wants to use flow control. You should first try to tell the concentrator not to use flow control. If you succeed in this, try making the terminal work without flow control, as described in the preceding section. If that line of approach is not successful, map some other characters into C-s and C-q using keyboard-translate-table. The example above shows how to do this with C-^ and C-\. * Control-S and Control-Q commands are ignored completely on a net connection. Some versions of rlogin (and possibly telnet) do not pass flow control characters to the remote system to which they connect. On such systems, emacs on the remote system cannot disable flow control on the local system. One way to cure this is to disable flow control on the local host (the one running rlogin, not the one running rlogind) using the stty command, before starting the rlogin process. On many systems, "stty start u stop u" will do this. Some versions of tcsh will prevent even this from working. One way around this is to start another shell before starting rlogin, and issue the stty command to disable flow control from that shell. If none of these methods work, the best solution is to type M-x enable-flow-control at the beginning of your emacs session, or if you expect the problem to continue, add a line such as the following to your .emacs (on the host running rlogind): (enable-flow-control-on "vt200" "vt300" "vt101" "vt131") See the entry about spontaneous display of I-search (above) for more info. * Screen is updated wrong, but only on one kind of terminal. This could mean that the termcap entry you are using for that terminal is wrong, or it could mean that Emacs has a bug handing the combination of features specified for that terminal. The first step in tracking this down is to record what characters Emacs is sending to the terminal. Execute the Lisp expression (open-termscript "./emacs-script") to make Emacs write all terminal output into the file ~/emacs-script as well; then do what makes the screen update wrong, and look at the file and decode the characters using the manual for the terminal. There are several possibilities: 1) The characters sent are correct, according to the terminal manual. In this case, there is no obvious bug in Emacs, and most likely you need more padding, or possibly the terminal manual is wrong. 2) The characters sent are incorrect, due to an obscure aspect of the terminal behavior not described in an obvious way by termcap. This case is hard. It will be necessary to think of a way for Emacs to distinguish between terminals with this kind of behavior and other terminals that behave subtly differently but are classified the same by termcap; or else find an algorithm for Emacs to use that avoids the difference. Such changes must be tested on many kinds of terminals. 3) The termcap entry is wrong. See the file etc/TERMS for information on changes that are known to be needed in commonly used termcap entries for certain terminals. 4) The characters sent are incorrect, and clearly cannot be right for any terminal with the termcap entry you were using. This is unambiguously an Emacs bug, and can probably be fixed in termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c. * Output from Control-V is slow. On many bit-map terminals, scrolling operations are fairly slow. Often the termcap entry for the type of terminal in use fails to inform Emacs of this. The two lines at the bottom of the screen before a Control-V command are supposed to appear at the top after the Control-V command. If Emacs thinks scrolling the lines is fast, it will scroll them to the top of the screen. If scrolling is slow but Emacs thinks it is fast, the usual reason is that the termcap entry for the terminal you are using does not specify any padding time for the `al' and `dl' strings. Emacs concludes that these operations take only as much time as it takes to send the commands at whatever line speed you are using. You must fix the termcap entry to specify, for the `al' and `dl', as much time as the operations really take. Currently Emacs thinks in terms of serial lines which send characters at a fixed rate, so that any operation which takes time for the terminal to execute must also be padded. With bit-map terminals operated across networks, often the network provides some sort of flow control so that padding is never needed no matter how slow an operation is. You must still specify a padding time if you want Emacs to realize that the operation takes a long time. This will cause padding characters to be sent unnecessarily, but they do not really cost much. They will be transmitted while the scrolling is happening and then discarded quickly by the terminal. Most bit-map terminals provide commands for inserting or deleting multiple lines at once. Define the `AL' and `DL' strings in the termcap entry to say how to do these things, and you will have fast output without wasted padding characters. These strings should each contain a single %-spec saying how to send the number of lines to be scrolled. These %-specs are like those in the termcap `cm' string. You should also define the `IC' and `DC' strings if your terminal has a command to insert or delete multiple characters. These take the number of positions to insert or delete as an argument. A `cs' string to set the scrolling region will reduce the amount of motion you see on the screen when part of the screen is scrolled. * Your Delete key sends a Backspace to the terminal, using an AIXterm. The solution is to include in your .Xdefaults the lines: *aixterm.Translations: #override BackSpace: string(0x7f) aixterm*ttyModes: erase ^? This makes your Backspace key send DEL (ASCII 127). * You type Control-H (Backspace) expecting to delete characters. Put `stty dec' in your .login file and your problems will disappear after a day or two. The choice of Backspace for erasure was based on confusion, caused by the fact that backspacing causes erasure (later, when you type another character) on most display terminals. But it is a mistake. Deletion of text is not the same thing as backspacing followed by failure to overprint. I do not wish to propagate this confusion by conforming to it. For this reason, I believe `stty dec' is the right mode to use, and I have designed Emacs to go with that. If there were a thousand other control characters, I would define Control-h to delete as well; but there are not very many other control characters, and I think that providing the most mnemonic possible Help character is more important than adapting to people who don't use `stty dec'. If you are obstinate about confusing buggy overprinting with deletion, you can redefine Backspace in your .emacs file: (global-set-key "\b" 'delete-backward-char) You may then wish to put the function help-command on some other key. I leave to you the task of deciding which key. * Editing files through RFS gives spurious "file has changed" warnings. It is possible that a change in Emacs 18.37 gets around this problem, but in case not, here is a description of how to fix the RFS bug that causes it. There was a serious pair of bugs in the handling of the fsync() system call in the RFS server. The first is that the fsync() call is handled as another name for the close() system call (!!). It appears that fsync() is not used by very many programs; Emacs version 18 does an fsync() before closing files to make sure that the bits are on the disk. This is fixed by the enclosed patch to the RFS server. The second, more serious problem, is that fsync() is treated as a non-blocking system call (i.e., it's implemented as a message that gets sent to the remote system without waiting for a reply). Fsync is a useful tool for building atomic file transactions. Implementing it as a non-blocking RPC call (when the local call blocks until the sync is done) is a bad idea; unfortunately, changing it will break the RFS protocol. No fix was supplied for this problem. (as always, your line numbers may vary) % rcsdiff -c -r1.2 serversyscall.c RCS file: RCS/serversyscall.c,v retrieving revision 1.2 diff -c -r1.2 serversyscall.c *** /tmp/,RCSt1003677 Wed Jan 28 15:15:02 1987 --- serversyscall.c Wed Jan 28 15:14:48 1987 *************** *** 163,169 **** /* * No return sent for close or fsync! */ ! if (syscall == RSYS_close || syscall == RSYS_fsync) proc->p_returnval = deallocate_fd(proc, msg->m_args[0]); else { --- 166,172 ---- /* * No return sent for close or fsync! */ ! if (syscall == RSYS_close) proc->p_returnval = deallocate_fd(proc, msg->m_args[0]); else { * Vax C compiler bugs affecting Emacs. You may get one of these problems compiling Emacs: foo.c line nnn: compiler error: no table entry for op STASG foo.c: fatal error in /lib/ccom These are due to bugs in the C compiler; the code is valid C. Unfortunately, the bugs are unpredictable: the same construct may compile properly or trigger one of these bugs, depending on what else is in the source file being compiled. Even changes in header files that should not affect the file being compiled can affect whether the bug happens. In addition, sometimes files that compile correctly on one machine get this bug on another machine. As a result, it is hard for me to make sure this bug will not affect you. I have attempted to find and alter these constructs, but more can always appear. However, I can tell you how to deal with it if it should happen. The bug comes from having an indexed reference to an array of Lisp_Objects, as an argument in a function call: Lisp_Object *args; ... ... foo (5, args[i], ...)... putting the argument into a temporary variable first, as in Lisp_Object *args; Lisp_Object tem; ... tem = args[i]; ... foo (r, tem, ...)... causes the problem to go away. The `contents' field of a Lisp vector is an array of Lisp_Objects, so you may see the problem happening with indexed references to that. * 68000 C compiler problems Various 68000 compilers have different problems. These are some that have been observed. ** Using value of assignment expression on union type loses. This means that x = y = z; or foo (x = z); does not work if x is of type Lisp_Object. ** "cannot reclaim" error. This means that an expression is too complicated. You get the correct line number in the error message. The code must be rewritten with simpler expressions. ** XCONS, XSTRING, etc macros produce incorrect code. If temacs fails to run at all, this may be the cause. Compile this test program and look at the assembler code: struct foo { char x; unsigned int y : 24; }; lose (arg) struct foo arg; { test ((int *) arg.y); } If the code is incorrect, your compiler has this problem. In the XCONS, etc., macros in lisp.h you must replace (a).u.val with ((a).u.val + coercedummy) where coercedummy is declared as int. This problem will not happen if the m-...h file for your type of machine defines NO_UNION_TYPE. That is the recommended setting now. * C compilers lose on returning unions I hear that some C compilers cannot handle returning a union type. Most of the functions in GNU Emacs return type Lisp_Object, which is defined as a union on some rare architectures. This problem will not happen if the m-...h file for your type of machine defines NO_UNION_TYPE.