Information For Maintainers of GNU Software

Richard Stallman last updated April 8, 1999

Copyright \begin{matrix}c \\ ◯ \end{matrix} 1992, 1993, 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Free Software Foundation.

1 About This Document

This file contains guidelines and advice for someone who is the maintainer of a GNU program on behalf of the GNU project. Anyone can change GNU software, and you need not read this file just to do that. But if you want to maintain a version for widespread distribution, then this file becomes important for you.

Please send corrections or suggestions for this document to gnu@gnu.org. If you make a suggestion, please include a suggested new wording for it; our time is limited. We prefer a context diff to the ‘maintain.texi’ file, but if you don’t have that file, please mail your suggestion anyway.

This document uses the gender-neutral third-person pronouns “person”, “per”, “pers” and “perself.” They are used just like “she”, “her”, “hers” and “herself”, except that they have no implications about gender. For example, “Person placed per new program under the GNU GPL, to let the public benefit from per work, and to enable person to think well of perself.” These pronouns were promoted, and perhaps invented, by Marge Piercy in Woman on the Edge of Time.

The directory ‘/gd/gnuorg’ is found on the GNU machines; if you are the maintainer of a GNU package, you should have an account on them. Contact gnu@gnu.org if you don’t have one. ‘/gd/gnu/maintain.tar.gz’ is a tar file containing all of these files in that directory which are mentioned in this file; it is updated daily.

This release of the GNU Maintenance Instructions was last updated April 8, 1999.

2 Legal Matters

When incorporating changes from other people, make sure to follow the correct procedures. Doing this ensures that the FSF has the legal right to distribute and defend GNU software.

2.1 Copyrights

This section applies if the package you are maintaining is copyright Free Software Foundation.

For the sake of registering the copyright on later versions of the software, you need to keep track of each person who makes significant changes. A change of ten lines or so, or a few such changes, in a large program is not significant.

Before incorporating significant changes, make sure that person has signed copyright papers and that the Free Software Foundation has received and signed them.

To check whether papers have been received, look in ‘/gd/gnuorg/copyright.list’. If you can’t look there directly, fsf-records@gnu.org can check for you, and can also check for papers that are waiting to be entered and inform you when expected papers arrive.

The directory ‘/gd/gnuorg’ is found on the GNU machines; if you are the maintainer of a GNU package, you should have an account on them. Contact gnu@gnu.org if you don’t have one.

In order for the contributor to know person should sign papers, you need to ask for the necessary papers. If you don’t know per well, and you don’t know that person is used to our ways of handling copyright papers, then it might be a good idea to raise the subject with a message like this:

Would you be willing to assign the copyright to the Free Software Foundation, so that we could install it in ….

or Would you be willing to sign a copyright disclaimer to put this change in the public domain, so that we can install it in ….

If person wants more information, you can send per ‘/gd/gnuorg/conditions.text’, which explains per options (assign vs. disclaim) and their consequences.

Once the conversation is under way and the contributor is ready for more details, you should send one of the templates that are found in ‘/gd/gnuorg’. This section explains which templates you should use in which circumstances. Please don’t use any of the templates except for those listed here, and please don’t change the wording.

Once the conversation is under way, you can send the contributor the precise wording and instructions by email. Before you do this, make sure to get the current version of the template you will use! We change these templates occasionally—don’t keep using an old version.

For large changes, ask the person for an assignment. Send the person a copy of the file ‘/gd/gnuorg/assign.changes’, but first, go to the second page and insert per name and the name of the program involved in place of ‘NAME OF PERSON’ and ‘NAME OF PROGRAM’. Do this before sending, because otherwise person might sign without noticing them. Then the papers would be useless.

For medium to small changes, ask per to fill out and return the disclaimer in the file

‘/gd/gnuorg/disclaim.changes’.

If the contributor is likely to keep making changes, person might want to sign an assignment for all per future changes to the program. So it is useful to offer per that alternative. If person is interested, send per the template in ‘/gd/gnuorg/assign.future’.

Before signing this, person needs to ask per employer for a disclaimer-in-advance; the template for this is in ‘/gd/gnuorg/disclaim.future’, so you should send that file as well as ‘assign.future’. (It is more convenient to send them in separate messages.)

We need legal papers for changes in manuals as well as for changes in software. For smaller changes, use ‘/gd/gnuorg/disclaim.changes.manual’; for larger ones, use ‘/gd/gnuorg/assign.changes.manual’. To cover both past and future changes to a

manual, you can use ‘/gd/gnuorg/assign.future.manual’.

If a contributor is reluctant to sign an assignment for a large change, and is willing to sign a disclaimer instead, that is acceptable, so you should offer this alternative if it seems useful. While we prefer an assignment for a larger change, so that we can enforce the GNU GPL for the new text, a disclaimer is enough to let us use the text.

If you maintain a collection of programs, occasionally someone will contribute an entire separate program or manual that should be added to the collection. Then you can use the

files ‘assign.program’, ‘disclaim.program’, ‘assign.manual’, and ‘disclaim.manual’.

We very much prefer an assignment for a new separate program or manual, unless it is quite small, but a disclaimer is sufficient to let us use the work.

Although there are other templates besides the ones listed here, they are for special circumstances; please do not use them without getting advice from Richard Stallman.

If you are not sure what to do, then please ask Richard Stallman for advice; if the contributor asks you questions about the meaning and consequences of the legal papers, and you don’t know the answers, you can forward them to Stallman.

Please do not try changing the wording of a template yourself. If you think a change is needed, please talk with Richard Stallman, who will work with a lawyer to decide what to do.

2.2 Copyright Notices

You should maintain copyright notices in all files of the program. A copyright notice looks like this:

Copyright 19xx, 19yy, 19zz copyright-holder The copyright-holder may be the Free Software Foundation, Inc., or someone else; you

should know who is the copyright holder for your package.

The list of year numbers should include each year in which you finished preparing a version which was actually released, and which was an ancestor of the current version.

It is important to understand that rule carefully, much as you would understand a complicated C statement in order to hand-simulate it.

This list is not a list of years in which versions were released. It is a list of years in which versions, later released, were completed. So if you finish a version on Dec 31, 1994 and release it on Jan 1, 1995, this version requires the inclusion of 1994, but doesn’t require the inclusion of 1995.

The versions that matter, for purposes of this list, are versions that were ancestors of the current version. So if you made a temporary branch in maintenance, and worked on branches A and B in parallel, then each branch would have its own list of years, which is based on the versions released in that branch. A version in branch A need not be reflected in the list of years for branch B, and vice versa.

However, if you copy code from branch A into branch B, the years for branch A (or at least, for the parts that you copied into branch B) do need to appear in the list in branch B, because now they are ancestors of branch B.

We agree that this rule is complicated. If we were in charge of copyright law, we would probably change this (as well as lots more).

2.3 Recording Changes

Keep records of which portions were written by whom.

These records don’t need to be as detailed as a change log. They don’t need to distinguish work done at different times, only different people.

They should say which files or functions were written by each person, and which files or functions were revised by each person. They don’t need to say what the purpose of the change was. The Register of Copyrights doesn’t care what the program does.

For example, this would describe an early version of GAS:

Dean Elsner first version of all files except gdb-lines.c and m68k.c. Jay Fenlason entire files gdb-lines.c and m68k.c, most of app.c, extensive changes in messages.c, input-file.c, write.c, revisions elsewhere.

Please keep these records in a file named ‘AUTHORS’ in the source directory for the program itself.

3 Cleaning Up Changes

If someone sends you changes which are ugly and will make the program harder to understand and maintain in the future, such as a port to another operating system containing ad hoc conditionals, don’t hesitate to ask person to clean up per changes before you merge them.

Since the amount of work we do is constant in any case, the more work we get other people to do, the faster GNU will advance.

If person will not or can not make the changes clean enough, then say that you can’t afford to merge them. Invite per to distribute per changes another way, or to find other people who can make them clean enough for us to maintain.

The only reason to do these cleanups yourself is if (1) it is easy enough that it is less work than telling the author what to clean up, or (2) users will greatly appreciate the improvement, and you would almost write it yourself if you had time.

The GNU Coding Standards are a good thing to send people who have to clean up C programs (see section “Contents” in GNU Coding Standards). The Emacs Lisp manual contains an appendix that gives coding standards for Emacs Lisp programs; it is good to urge authors to read it (see section “Tips and Standards” in The GNU Emacs Lisp Reference Manual).

4 Dealing With Mail

Once a program is in use, you will start getting bug reports. Some GNU programs have their own special lists for sending bug reports. For miscellaneous programs that don’t have their own lists, we use a catch-all list, bug-gnu-utils@gnu.org. Many lists are handled by smartlist; for those lists, you can send mail to the -request address to subscribe; otherwise, talk with gnu@gnu.org to arrange to be added to the proper list for your program. To set up a new list, you should also talk with gnu@gnu.org.

When you receive bug reports, keep in mind that bug reports are crucial for your work. If you don’t know about problems, you cannot fix them. So always thank the people who send bug reports.

You don’t have an obligation to give more response than that, though. The main purpose of bug reports is to help you to improve the next version of the program. Many of the people who report bugs don’t realize this–they think that the point is for you to help them individually. Some will ask to focus on that instead of on making the program better. That isn’t part of the job you have undertaken, so you shouldn’t feel an obligation to satisfy them.

For example, people sometimes report a bug in a vague (and therefore useless) way, and when you ask for more information, they say, “I just wanted to see if you already knew the solution” (in which case the bug report is certainly useless). When this happens, you should explain to them what bug reports are really for.

When people ask you to put your time into helping them use the program, it may seem “helpful” to do what they ask. But it is much less helpful than improving the program, which is the maintainer’s real job. If you spend significant time helping one person, when you could instead have helped thousands, the world as a whole is worse off.

So be careful to limit the amount of time you spend giving in to those requests—don’t let them take priority over maintaining the program. Spend time helping individual users when you feel like it, when you feel you have the time available. But know how to say no to them, also; if you feel really pressed for time, just “thanks for the bug report” is enough response.

5 Recording Old Versions

It is very important to keep backup files of all source files of GNU. You can do this using RCS, CVS or PRCS if you like. The easiest way to use RCS or CVS is via the Version Control library in Emacs; section “Concepts of Version Control” in The GNU Emacs Manual.

Alternatively, you can keep backup files.

5.1 Backup Files

Emacs makes a backup file by renaming the old source file to a new name. This means that if the file is also pointed to by a distribution directory, the distribution directory continues to point to the same version it always did—the right thing.

We want to keep more than one backup for all GNU sources. So, if you are going to edit GNU sources, make certain to put

     (setq version-control t)

into your ‘.emacs’ file, so that Emacs always creates numbered backup files.

Using Emacs backup files works as long as people always make changes with Emacs. If you change the file in some other way, and use cp, ftp, or tar to install it, you will overwrite the old version and fail to make a backup. Don’t do that!

If you want to make a change to a source file with something other than Emacs, you can write the changed file to another name, and use C-x C-w in Emacs to write it under the real name. This makes the backup file properly.

You can use GNU cp or mv to install changed files if you give them the ‘--backup’ (or, equivalently, ‘-b’) option; then they make backup copies the same way that Emacs does. You should also use the ‘--version-control=t’ option, or, alternately, first

     export VERSION_CONTROL=t

(or the csh equivalent); this makes GNU cp and mv create numbered backup files instead of a single backup file with a ‘~’ appended to the filename. For installing many changed files, you can use shell wildcards and also give GNU cp or mv the ‘--update’ (‘-u’) option, which only copies (or moves) files that have been modified more recently than the existing destination files, and the ‘--verbose’ (‘-v’) option, which prints the names of the files that are actually copied (or moved).

Before you use mv or cp in this way, make sure it is the GNU version. Do ‘which mv’ (in csh) or ‘type mv’ (in bash) to verify you are not getting ‘/bin/mv’ (or likewise for cp). Or just type ‘cp’ or ‘mv’ and look at the usage message.

5.2 Deleting Backup Files

Always answer no when Emacs offers to delete backup files automatically. The way to delete them is by hand, using M-x dired.

When you decide which backup files to delete, it is good to keep one every couple of weeks or so, going back about 2 months.

If there is a long gap between versions, because that file did not change during a long period of time, then keep the version before the gap even if it is 2 months old. Pretend it is just 2 weeks older than the next kept version, so delete it when the next version is >= 6 weeks old.

If the changes in a program have been simple, then you don’t need to keep as many backup files. Just one a month for 2 months is enough.

If you have made big changes, keep the versions before and after the big change, until they are old enough.

If you made several changes the same day, usually the last version written that day is best to keep.

It is almost always right to keep the most recent backup version.

6 Distributions

It is important to follow the GNU conventions when making GNU software distributions.

6.1 Distribution tar Files

The tar file for version m.n of program foo should be named ‘foo-m.n.tar’. It should unpack into a subdirectory named ‘foo-m.n’. Tar files should not unpack into files in the current directory, because this is inconvenient if the user happens to unpack into a directory with other files in it.

Here is how the ‘Makefile’ for Bison creates the tar file. This method is good for other programs.

     dist: bison.info
             echo bison-`sed -e '/version_string/!d' \
               -e 's/[^0-9.]*\([0-9.]*\).*/\1/' -e q version.c` > .fname
             -rm -rf `cat .fname`
             mkdir `cat .fname`
             dst=`cat .fname`; for f in $(DISTFILES); do \
                ln $(srcdir)/$$f $$dst/$$f || { echo copying $$f; \
                  cp -p $(srcdir)/$$f $$dst/$$f ; } \

             done
             tar --gzip -chf `cat .fname`.tar.gz `cat .fname`
             -rm -rf `cat .fname` .fname

Source files that are symbolic links to other file systems cannot be installed in the temporary directory using ln, so use cp if ln fails.

Using Automake is a good way to take care of writing the dist target.

6.2 Distribution Patches

If the program is large, it is useful to make a set of diffs for each release, against the previous important release.

At the front of the set of diffs, put a short explanation of which version this is for and which previous version it is relative to. Also explain what else people need to do to update the sources properly (for example, delete or rename certain files before installing the diffs).

The purpose of having diffs is that they are small. To keep them small, exclude files that the user can easily update. For example, exclude info files, DVI files, tags tables, output files of Bison or Flex. In Emacs diffs, we exclude compiled Lisp files, leaving it up to the installer to recompile the patched sources.

When you make the diffs, each version should be in a directory suitably named—for example, ‘gcc-2.3.2’ and ‘gcc-2.3.3’. This way, it will be very clear from the diffs themselves which version is which.

If you use GNU diff to make the patch, use the options ‘-rc2P’. That will put any new files into the output as “entirely different.” Also, the patch’s context diff headers should have dates and times in Universal Time using traditional Unix format, so that patch recipients can use GNU patch’s ‘-Z’ option. For example, you could use the following Bourne shell command to create the patch:

     LC_ALL=C TZ=UTC0 diff -rc2P gcc-2.3.2 gcc-2.3.3 | \
     gzip -9 >gcc-2.3.2-2.3.3.patch.gz

If the distribution has subdirectories in it, then the diffs probably include some files in the subdirectories. To help users install such patches reliably, give them precise directions for how to run patch. For example, say this:

To apply these patches, cd to the main directory of the program and then use ‘patch -p1’. ‘-p1’ avoids guesswork in choosing which subdirectory to find each file in.

It’s wise to test your patch by applying it to a copy of the old version, and checking that the result exactly matches the new version.

6.3 Distribution on ftp.gnu.org

Only the latest version of any program needs to be on ftp.gnu.org. Being an archive of old versions is not the function of ftp.gnu.org.

Diffs are another matter. Since they are much smaller than distribution files, it is good to keep the diffs around for quite a while.

6.4 Test Releases

When you release a greatly changed new major version of a program, you might want to do so as a beta test release.

Once a program gets to be widely used and people expect it to work solidly, it is a good idea to do pretest releases before each “real” release. This means that you make a tar file, but send it only to a group of volunteers that you have recruited. (Use a suitable GNU mailing list/newsgroup to recruit them.)

One thing that you should never do is to release a distribution which is considered a pretest or beta test but which contains the version number for the planned real release. Many people will look only at the version number (in the tar file name, in the directory name that it unpacks into, or wherever they can find it) to determine whether a tar file is the latest version. People might look at the test release in this way and mistake it for the real release. Therefore, always change the number when you make a new tar file.

If you are about to release version 4.6 but you want to do a pretest or beta test first, call it 4.5.90. If you need a second pretest, call it 4.5.91, and so on.

7 Using the Proofreaders List

If you want help finding errors in documentation, or help improving the quality of writing, or if you are not a native speaker of English and want help producing good English documentation, you can use the GNU proofreaders mailing list: proofreaders@gnu.org.

But be careful when you use the list, because there are over 200 people on it. If you simply ask everyone on the list to read your work, there will probably be tremendous duplication of effort by the proofreaders, and you will probably get the same errors reported 100 times. This must be avoided.

Also, the people on the list do not want to get a large amount of mail from it. So do not ever ask people on the list to send mail to the list!

Here are a few methods that seem reasonable to use:

• For something small, mail it to the list, and ask people to pick a random number from 1 to 20, and read it if the number comes out as 10. This way, assuming 50% response, some 5 people will read the piece.

• For a larger work, divide your work into around 20 equal-sized parts, tell people where to get it, and ask each person to pick randomly which part to read. Be sure to specify the random choice procedure; otherwise people will probably use a mental procedure that is not really random, such as "pick a part near the middle", and you will not get even coverage. You can either divide up the work physically, into 20 separate files, or describe a virtual division, such as by sections (if your work has approximately 20 sections). If you do the latter, be sure to be precise about it—for example, do you want the material before the first section heading to count as a section, or not?

• For a job needing special skills, send an explanation of it, and ask people to send you mail if they volunteer for the job. When you get enough volunteers, send another message to the list saying "I have enough volunteers, no more please."

Table of Contents

1 About This Document . . . . . . . . . . . . . . . . . . . . . 1

2 Legal Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.1 Copyrights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.2 Copyright Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.3 Recording Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 Cleaning Up Changes . . . . . . . . . . . . . . . . . . . . . . 4

4 Dealing With Mail . . . . . . . . . . . . . . . . . . . . . . . . . 4

5 Recording Old Versions . . . . . . . . . . . . . . . . . . . . 5

5.1 Backup Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5.2 Deleting Backup Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6 Distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6.1 Distribution tar Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6.2 Distribution Patches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.3 Distribution on ftp.gnu.org. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6.4 Test Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

7 Using the Proofreaders List . . . . . . . . . . . . . . . . 8