UPDATING revision 1.380
1$NetBSD: UPDATING,v 1.380 2025/05/28 07:19:32 martin Exp $
2
3This file (UPDATING) is intended to be a brief reference to recent
4changes that might cause problems in the build process, and a guide for
5what to do if something doesn't work.
6
7For a more detailed description of the recommended way to build NetBSD
8using build.sh, see the BUILDING file.
9
10Note that much of the advice in this UPDATING file was written before
11build.sh existed.  Nevertheless, the advice here may be useful for
12working around specific problems with build.sh.
13
14Sections are marked with "^^^^^".  After the section on "Recent changes"
15are several sections containing more general information.
16
17See also: BUILDING, build.sh, Makefile.
18
19Recent changes:
20^^^^^^^^^^^^^^^
21
2220250528:
23	Changes in the tools build require removing all config.cache
24	files in the object tools directories.
25
2620250427:
27	The KERNEL_DIR option to build.sh is now functional.  Set it
28	with ``-V KERNEL_DIR=yes'' on your build.sh command.
29	With this, you can now colocate kernel and associated modules
30	in /netbsd/{kernel,kernel.dbg,modules} instead of having the
31	kernel in / but modules in /stand.
32
33	Note that you'll need new bootstrap code to use this feature.
34
35	This completes work begun many years ago by christos@ :-)
36
3720250413:
38	A change to bsd.lib.mk requires a clean build of all libraries.
39
4020250131:
41	The switch to the new jemalloc requires cleaning in libc.
42
4320241122:
44	Changes to various libraries' build options require cleaning
45	their objdirs in update builds:
46
47	cd external/bsd/file/lib && $TOOLDIR/bin/nbmake-$ARCH clean
48	cd external/bsd/libarchive/lib && $TOOLDIR/bin/nbmake-$ARCH clean
49	cd external/public-domain/xz/lib && $TOOLDIR/bin/nbmake-$ARCH clean
50
51	Also, for architectures with MKCOMPAT, it is necessary to clean
52	the compat objdirs too.  The easiest way is:
53
54	rm -rf OBJDIR/compat/*/*/external/bsd/file/lib
55	rm -rf OBJDIR/compat/*/*/external/bsd/libarchive/lib
56	rm -rf OBJDIR/compat/*/*/external/public-domain/xz/lib
57
58	Changes to bsd.lib.mk to improve detecting differences in
59	shared library symbol exports may cause some .actsym files in
60	the objdir to become stale in update builds.
61
62	To work around this, delete all files matching `*.actsym' in
63	the objdir.  For example:
64
65	find OBJDIR -name '*.actsym' -type f -print0 | xargs -0 rm
66
6720241104:
68	Changes around the integration of the zstd compression
69	library may require manual deletion of some object directories
70	if you update from a build from a few days ago:
71	rm -rf DESTDIR/usr/lib/*/libarchive*
72	rm -rf DESTDIR/usr/lib/*/libmagic*
73	rm -rf DESTDIR/usr/lib/*/libzstd*
74	rm -rf DESTDIR/usr/lib/libarchive*
75	rm -rf DESTDIR/usr/lib/libmagic*
76	rm -rf DESTDIR/usr/lib/libzstd*
77	rm -rf OBJDIR/compat/*/*/external/bsd/file/
78	rm -rf OBJDIR/compat/*/*/external/bsd/libarchive/
79	rm -rf OBJDIR/compat/*/*/external/bsd/zstd/
80	rm -rf OBJDIR/external/bsd/file/
81	rm -rf OBJDIR/external/bsd/libarchive/
82	rm -rf OBJDIR/external/bsd/zstd/
83	rm -rf OBJDIR/external/gpl3/gcc/
84	rm -rf OBJDIR/tools/gcc/
85
8620240926:
87	Building -current when running on amd64 from about 20240924
88	to about 20240926 will not work due to a "malloc_np.h"
89	error. Please downgrade to a version from 20240924 or older,
90	or upgrade to a newer version e.g. using a binary release from
91	the NetBSD build servers.
92
9320240923:
94	Update builds will require cleaning the object directories for
95	jemalloc (like: "rm -rf $OBJ/external/bsd/jemalloc*") and the
96	libc dependency files (like: "rm $OBJ/lib/libc/jemalloc.*").
97	On architectures with COMPAT libs, those also have to be cleaned,
98	e.g. on sparc64: "rm -rf $OBJ/compat/sparc64/sparc/external/bsd/jemalloc*"
99	and "rm $OBJ/compat/sparc64/sparc/lib/libc/jemalloc.*".
100
10120240817:
102	Update builds will require cleaning in src/external/historical/nawk/bin
103	in order to remove the awk binary since now there is a subdirectory
104	called awk.
105
10620240812:
107	Update builds will require removing the tools objdir for gdb
108	if building with MKCROSSGDB=yes. All architectures use gdb.old
109	now.
110
11120240630:
112	Update builds will require removing the tools objdir for binutils
113	(as most architectures should use binutils.old now).
114
11520240610:
116	Update builds are likely to require removing the objdir for
117	distrib/<arch>/cdroms - or at least references to libarchive
118	from within there after the recent libarchive update.
119
12020240504:
121	Update builds on x86 require making the `cleandir' target in
122	lib/libm, or deleting the objdir for lib/libm.
123
12420240423:
125	Update builds with x11 may fail after switching to Mesa 21.
126
12720240410:
128	Update builds may require manually deleting
129	$DESTDIR/var/run/named (and, potentially,
130	$DESTDIR/var/run/lwresd) in order to avoid checkflist failure.
131
13220240409:
133	32-bit compatibility libraries were moved into the base32
134	and debug32 sets.  HTML man pages were moved into the manhtml set.
135
13620230828:
137	If:
138        - you updated to current and ran postinstall between 20230826
139	  and 20230828 inclusive, and
140        - you are not using anything outside the base system to
141	  populate /etc/openssl/certs (e.g., manually adding
142	  certificates or using ca-certificates or mozilla-rootcerts or
143	  mozilla-rootcerts-openssl from pkgsrc),
144	delete /etc/openssl/certs and rerun postinstall or just
145	`certctl rehash'.
146
147	Otherwise, certctl(8) will think someone else has left
148	/etc/openssl/certs in the way and will avoid clobbering it on
149	upgrade from older NetBSD.
150
15120230718:
152	build.sh will use mk.conf in the same directory as build.sh instead
153	of /etc/mk.conf, unless MAKECONF is already defined in the environment.
154
15520230714:
156	Import of gcc 10.5 requires a clean build of at least tools/gcc
157	and external/gpl3/gcc* object directories. An update build
158	without cleaning will result in obscure failures in rare corner
159	cases.
160
16120230604:
162	Building native kernels with the installed make(1) instead of
163	the $TOOLDIR/bin/nbmake-${arch} wrapper will fail if userland
164	has not been updated. Note that this is an unsupported build
165	configuration (but usually works if userland is -current enough).
166
16720230523:
168	ctfmerge was fixed as macOS host tool. This may require a clean tools
169	rebuild to detect the update to tools/compat/configure.
170
17120230515:
172	New openssl build requires removal of the crypto/external/bsd/openssl
173	and tests/crypto/libcrypto subdirectories in the ${OBJDIR} hierarchy.
174	Otherwise test results may be wrong due to wrong "golden" output
175	files being installed.
176
17720230322:
178	Fixes for moved /lib/libisns* mean that builds will complain about
179	./usr/lib/libisns* being missing until src/lib/libisns is forced
180	to (re)install the files, including the symlinks.  The simplest
181	way is to clean this subdir before building.
182
18320230112:
184	New binutils require an updated ld.elf_so. If you are doing
185	(unsupported) in-place self builds (with the -E flag to build.sh),
186	make sure to have installed latest ld.elf_so before you rebuild
187	userland.
188
18920221116:
190	The addition to NetBSD's version of UFS2 of support for extended
191	attributes broke backward compatibility with previous releases
192	of NetBSD, so UFS2 has been restored to being compatible with
193	previous NetBSD releases by disabling extended attributes.
194	(Note that ACLs are implemented as extended attributes, so
195	this changes disables ACLs as well.)
196
197	Support for UFS2 with extended attributes is now available in a new
198	UFS variant called UFS2ea.  If you have created extended attributes
199	in an original UFS2 file system then "fsck -p" will now fail due to
200	the unexpected presence of extended attributes and "fsck -y" will
201	remove all extended attributes.  If you wish to preserve extended
202	attributes rather than delete them, there is a utility to convert
203	a UFS2 file system to UFS2ea and leave extended attributes in place,
204	but this should be used with caution since it will preserve any
205	extended attributes that have been corrupted by the backward
206	incompatibility too.
207
208	If you wish to use a UFS2ea file system as your root file system,
209	then you will need to update your boot loader to a version that
210	supports UFS2ea.
211
212	For more information, see:
213	https://wiki.netbsd.org/features/UFS2ea
214
21520221111:
216	The new libdrm import worsened the conflict issues for the
217	kdump/ktruss ioctl, and i915 now conflicts with base, and has
218	been turned off.  This will cause update build issues like:
219
220		kdump-ioctl.c:12175:143: error: 'DRM_IOCTL_I915_DESTROY_HEAP'
221		   undeclared here (not in a function);
222		   did you mean 'DRM_IOCTL_MODE_DESTROY_DUMB'?
223
224	You'll need to clean usr.bin/ktruss, usr.bin/kdump, and rescue.
225
22620220921:
227	Since the kernel version was bumped to 9.99.100, the bootloader
228	must be updated on x86 or EFI boot platforms in order to load
229	modules from boot.cfg(5) or interactively at the bootloader
230	prompt.
231
232	The kernel can still load modules at runtime, with modload(8)
233	or modules.conf(5), with no bootloader update.  This will not
234	affect release branches because it only applies to patch
235	numbers >=100.
236
237	On x86 (i386 or amd64) with BIOS boot, this requires copying a
238	new /usr/mdec/boot to /boot.  You can build this in the destdir
239	by running `$TOOLDIR/bin/nbmake-$ARCH dependall install' in
240	sys/arch/i386/stand.
241
242	On platforms with EFI boot (including x86 with EFI boot), this
243	requires copying a new /usr/mdec/boot*.efi to the EFI/BOOT/
244	directory on the EFI system partition.  The boot*.efi file is:
245
246	aarch64	bootaa64.efi
247	amd64	bootx64.efi
248	arm	bootarm.efi	(32-bit arm)
249	i386	bootx32.efi
250
251	You can build this in the destdir by running
252	`$TOOLDIR/bin/nbmake-$ARCH dependall install' in
253	sys/stand/efiboot/boot*.
254
25520220821:
256	Support for building extsrc/ has been deprecated.
257	EXTSRCSRCDIR and MKEXTSRC have been deprecated.
258
25920220714:
260	Updates to xorg-server and associated drivers may cause builds to
261	fail.  Cleaning both DESTDIR and the xorg build tree may be needed.
262
26320220628:
264	Changes in the build of src/games/robots require a clean build
265	of that program.
266
26720211116:
268	Changes in the xorg build require clean obj dirs for external/mit/xorg
269	(or a full clean/non-update build).
270
27120211112:
272	Device tree sources were updated for evbarm.  Some device nodes
273	(in particular, ld(4) devices on the ROCKPro64) will be renumbered.
274
27520211014:
276	MKPIE default for aarch64 has changed, a clean build is required.
277
27820210917:
279	Changed MNT_ACLS to default to POSIX1e ACLs instead of NFSv4
280	ACLs, to be compatible with FreeBSD. If you are using NFSv4 ACLs
281	and have "acls" in /etc/fstab you'll need to change it to "nfs4acls".
282
28320210711:
284	Updated GMP sources may require cleaning in tools/gmp and/or in
285	external/lgpl3/gmp/lib, particularly if GCC itself does not build.
286
28720210417:
288	GCC 10 was enabled for several platforms.  If builds fail in either
289	tools/gcc or external/gpl3/gcc, first try cleaning those objects and
290	removing the $DESTDIR/usr/include/g++ subdirectory.
291
29220201016:
293	MIPS kernel modules have been disabled until they work.  This will
294	turn up in extra files in the DESTDIR, which should be cleaned.
295
29620200925:
297	GNU MPC and MPFR have been updated.  At least MPFR needs cleaning
298	in both the tools and external dirs.
299
30020200912:
301	GCC 9 has arrived for Arm and x86 platforms, and will be coming
302	for several more, as will binutils 2.34.  Clean as required.
303
30420200907:
305	GCC 9 is coming, and binutils has been updated for MIPS.  This
306	probably requires cleaning the tools/binutils.
307
30820200811:
309	GCC updates may require cleaning the objdir.  This may occur
310	due to GCC 7.5 update, GCC 8.4 move to gcc.old, or the upcoming
311	GCC 9 upgrade.
312
31320200614:
314	blacklist* has been renamed to blocklist*. postinstall(8)
315	should handle the migration.
316
31720200601:
318	Due to a mistake in LIBISPRIVATE handling, .so libraries were
319	created in the build directories and need cleaning.
320
32120200311:
322	GCC 8 ports will need cleaning in src/tools/gcc and
323	src/external/gpl3/gcc due to GCC 8.4 update.
324
32520191118:
326	More architectures were switched to gcc8:
327	    i386, ia64 powerpc64, sparc, sparc64, arm
328	The same comments as in 20191022 apply.
329
33020191112:
331	The LLVM update requires a clean rebuild for all architectures using
332	LLVM during the tools build phase (i386, amd64, aarch64).
333
33420191022:
335	Ports amd64 and aarch64 switched to GCC 8.3 by default.
336	In-place ("expert mode", build.sh -E) builds are not supported
337	when going from a GCC 7 userland to GCC 8. Do a regular
338	build to a different DESTDIR (or preferably: build.sh -U) at least
339	once and install sets, or download comp.{tar.xz,tgz} from the
340	daily builds and install that before doing the next in-place build.
341
34220191001:
343	GCC 8.3 was imported.  Builds of src/tools/gcc may fail if
344	old builds with GCC 7 output now uses GCC 8.  Clean this
345	directory, and also clean src/external/gpl3/gcc.
346
34720190903:
348	Files with names that coincide with existing files' names on
349	case-insensitive file systems were inadvertently committed, for
350	radeon GPU firmware.  We cannot mark these as obsolete for
351	postinstall to fix, so if you updated src since 2019-08-26, and
352	ran build.sh distribution or ran build.sh release, you must
353	manually delete the following files in your DESTDIR (which is
354	usually $OBJDIR/destir.$ARCH), or from / if you have installed
355	them:
356
357		/libdata/firmware/radeon/bonaire_ce.bin
358		/libdata/firmware/radeon/bonaire_mc.bin
359		/libdata/firmware/radeon/bonaire_me.bin
360		/libdata/firmware/radeon/bonaire_mec.bin
361		/libdata/firmware/radeon/bonaire_pfp.bin
362		/libdata/firmware/radeon/bonaire_rlc.bin
363		/libdata/firmware/radeon/bonaire_sdma.bin
364		/libdata/firmware/radeon/bonaire_smc.bin
365		/libdata/firmware/radeon/bonaire_uvd.bin
366		/libdata/firmware/radeon/hainan_ce.bin
367		/libdata/firmware/radeon/hainan_mc.bin
368		/libdata/firmware/radeon/hainan_me.bin
369		/libdata/firmware/radeon/hainan_pfp.bin
370		/libdata/firmware/radeon/hainan_rlc.bin
371		/libdata/firmware/radeon/hainan_smc.bin
372		/libdata/firmware/radeon/hawaii_ce.bin
373		/libdata/firmware/radeon/hawaii_mc.bin
374		/libdata/firmware/radeon/hawaii_me.bin
375		/libdata/firmware/radeon/hawaii_mec.bin
376		/libdata/firmware/radeon/hawaii_pfp.bin
377		/libdata/firmware/radeon/hawaii_rlc.bin
378		/libdata/firmware/radeon/hawaii_sdma.bin
379		/libdata/firmware/radeon/hawaii_smc.bin
380		/libdata/firmware/radeon/kabini_ce.bin
381		/libdata/firmware/radeon/kabini_me.bin
382		/libdata/firmware/radeon/kabini_mec.bin
383		/libdata/firmware/radeon/kabini_pfp.bin
384		/libdata/firmware/radeon/kabini_rlc.bin
385		/libdata/firmware/radeon/kabini_sdma.bin
386		/libdata/firmware/radeon/kaveri_ce.bin
387		/libdata/firmware/radeon/kaveri_me.bin
388		/libdata/firmware/radeon/kaveri_mec.bin
389		/libdata/firmware/radeon/kaveri_mec2.bin
390		/libdata/firmware/radeon/kaveri_pfp.bin
391		/libdata/firmware/radeon/kaveri_rlc.bin
392		/libdata/firmware/radeon/kaveri_sdma.bin
393		/libdata/firmware/radeon/mullins_ce.bin
394		/libdata/firmware/radeon/mullins_me.bin
395		/libdata/firmware/radeon/mullins_mec.bin
396		/libdata/firmware/radeon/mullins_pfp.bin
397		/libdata/firmware/radeon/mullins_rlc.bin
398		/libdata/firmware/radeon/mullins_sdma.bin
399		/libdata/firmware/radeon/oland_ce.bin
400		/libdata/firmware/radeon/oland_mc.bin
401		/libdata/firmware/radeon/oland_me.bin
402		/libdata/firmware/radeon/oland_pfp.bin
403		/libdata/firmware/radeon/oland_rlc.bin
404		/libdata/firmware/radeon/oland_smc.bin
405		/libdata/firmware/radeon/pitcairn_ce.bin
406		/libdata/firmware/radeon/pitcairn_mc.bin
407		/libdata/firmware/radeon/pitcairn_me.bin
408		/libdata/firmware/radeon/pitcairn_pfp.bin
409		/libdata/firmware/radeon/pitcairn_rlc.bin
410		/libdata/firmware/radeon/pitcairn_smc.bin
411		/libdata/firmware/radeon/tahiti_ce.bin
412		/libdata/firmware/radeon/tahiti_mc.bin
413		/libdata/firmware/radeon/tahiti_me.bin
414		/libdata/firmware/radeon/tahiti_pfp.bin
415		/libdata/firmware/radeon/tahiti_rlc.bin
416		/libdata/firmware/radeon/tahiti_smc.bin
417		/libdata/firmware/radeon/verde_ce.bin
418		/libdata/firmware/radeon/verde_mc.bin
419		/libdata/firmware/radeon/verde_me.bin
420		/libdata/firmware/radeon/verde_pfp.bin
421		/libdata/firmware/radeon/verde_rlc.bin
422		/libdata/firmware/radeon/verde_smc.bin
423
424	We will re-import these radeon firmware images another way
425	later.
426
42720190727:
428	The uefi bootloader has gained tftp support and needs a clean
429	build. If you do update builds, manually clean its object
430	directory by something like:
431	cd sys/arch/i386/stand/efiboot && make clean
432
43320190723:
434	The jemalloc allocator in libc is now built without extended
435	debugging (for performance reasons). In update builds make sure
436	to rebuild it completely, by removing all affected object files,
437	including compat builds, something like:
438	cd /usr/obj && find . -type d -name jemalloc|xargs rm -rf
439
44020190207:
441	GCC 7 switched for many ports.  Update builds are likely to fail.
442
443Hints for a more successful build:
444^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
445    Use build.sh, but do not use its "expert mode":
446	This will automatically build the tools in the
447	   correct order, and it will keep the tools and the
448	   new build products from interfering with the running
449	   system.  This will allow you to ignore most of the
450	   other advice in this file.
451    Build a new kernel first:
452	This makes sure that any new system calls or features
453	   expected by the new userland will be present.  This
454	   helps to avoid critical errors when upgrading.
455    Use object directories:
456	This helps to keep stale object
457	   files from polluting the build if a Makefile "forgets"
458	   about one.  It also makes it easier to clean up after
459	   a build.  It's also necessary if you want to use the
460	   same source tree for multiple machines.
461	   To use object directories with build.sh:
462	    a) invoke build.sh with the "-M" or "-O" options.
463	   To use object directories without using build.sh:
464	    a) cd /usr/src ; make cleandir
465	    b) Add "OBJMACHINE=yes" to /etc/mk.conf
466	    c) Add "MKOBJDIRS=yes" to /etc/mk.conf
467	    d) cd /usr/src ; make build
468	   Note that running "make obj" in a directory will create
469	   in obj.$MACHINE directory.
470    Build to a DESTDIR:
471	This helps to keep old installed files (especially libraries)
472	   from interfering with the new build.
473	   To build to a DESTDIR with build.sh, use the "-D" option.
474	   To build to a DESTDIR without using build.sh, set the DESTDIR
475	   environment variable before running make build.  It should be
476	   set to the pathname of an initially empty directory.
477	   Problems: if you do not use build.sh, you might need to
478		update critical utilities without using DESTDIR since
479		nothing is executed from what is installed in DESTDIR.
480		(See critical utils, below.)
481    Build often:
482	This keeps critical utilities current enough to not choke
483	on any other part of the source tree that depends on up to
484	date functionality.  If you use build.sh, you should not have
485	this problem.
486
487What to do if things don't work:
488^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
489When things don't work there are usually a few things that commonly
490should be done.
491    1)	make includes
492	This should be done automatically by make build.
493    2)  cd share/mk && make install
494	Again, automatically done by make build.
495
496Failsafe rebuild of a small part of the tree:
497^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
498To make sure you rebuild something correctly you want to do
499something like the following:
500    1)  Make sure the includes and .mk files are up to date.
501    2)  Make sure any program used to build the particular
502	utility is up to date.  (yacc, lex, etc...)
503    3)  cd ...path/to/util...
504	make cleandir
505	rm ...all obj directories...
506	make cleandir			# yes, again
507	make obj
508	make depend && make
509
510Failsafe rebuild of the entire tree:
511^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
512If you really want to make sure the source tree is clean and
513ready for a build try the following.  Note that sourcing /etc/mk.conf
514(a make(1) Makefile) in this manner is not right, and will not work
515for anyone who uses any make(1) features in /etc/mk.conf.
516
517---cut here---
518#!/bin/sh
519. /etc/mk.conf
520
521if [ -z $NETBSDSRCDIR ] ; then
522    NETBSDSRCDIR=/usr/src
523fi
524if [ \! -d $NETBSDSRCDIR ] ; then
525    echo Unable to find sources
526    exit 1
527fi
528find $NETBSDSRCDIR -name \*.o -o -name obj.\* -o -name obj -exec rm \{\} \;
529
530if [ -z $BSDOBJDIR ] ; then
531    BSDOBJDIR=/usr/obj
532fi
533if [ -d $BSDOBJDIR ] ; then
534    rm -rf $BSDOBJDIR
535fi
536
537cd $NETBSDSRCDIR && make cleandir
538
539---cut here---
540
541Critical utilities:
542^^^^^^^^^^^^^^^^^^^
543	usr.bin/make
544	usr.bin/yacc
545	usr.bin/lex
546	usr.bin/xlint
547	usr.bin/config
548
549Other problems and possible solutions:
550^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
551Symptom:Complaints involving a Makefile.
552Fix:	Rebuild usr.bin/make:
553	cd usr.bin/make && make && make install
554	Or, a failsafe method if that doesn't work:
555	cd usr.bin/make && cc -DMAKE_NATIVE *.c -I. -o make \
556	&& install make /usr/bin
557
558Fix:	Make sure .mk files are up to date.
559	cd share/mk && make install
560
561Symptom:Kernel `config' fails to configure any kernel, including GENERIC.
562Fix:	Rebuild usr.bin/config
563
564Symptom:Obsolete intermediate files are used during compilation
565Fix:	Try the following sequence of commands in the directory in question.
566	make cleandir; rm `make print-objdir`; make cleandir; make obj
567	(If you built the tree without "make obj" in the past, obsolete files
568	may remain.  The command tries to clean everything up)
569
570Symptom:.../sysinst/run.c:xx: warning: initialization from incompatible
571	pointer type
572Fix:	Rebuild and install usr.bin/menuc
573
574Symptom:mklocale not found during build in share/locale/ctype
575Fix:	Build and install usr.bin/mklocale
576
577Symptom:undefined reference to `__assert13' or `__unsetenv13'
578Fix:    Rebuild and install lib/libc
579
580Symptom:usr.bin/config fails to build.
581Fix:	Try building with -DMAKE_BOOTSTRAP added to CFLAGS in Makefile.
582
583Symptom:undefined reference to `getprogname' or `setprogname'
584Fix:    Rebuild and install lib/libc
585
586Symptom:Update build fails in src/tools/gcc complaining that a variable
587	(e.g. CPPFLAGS) has changed since the previous run.
588Fix:    Run "nbmake-${ARCH} clean" in src/tools/gcc or do a clean build.
589
590Symptom:cvs [update aborted]: cannot open directory /cvsroot/src/...:
591	No such file or directory.
592Cause:	If a directory is created by mistake, then it is sometimes
593	deleted from the CVS repository using administrative commands
594	that bypass the normal cvs access controls.  If your cvs working tree
595	contains references to a directory that has been deleted on the
596	server in this way, then "cvs update" reports this error.
597Fix:	Recursively delete the affected directory from your working tree
598	and try the update again.
599