aboutsummaryrefslogblamecommitdiffstats
path: root/INSTALL.md
blob: 1bc0df9fd8fd55549a56dc480ff0557347a6de10 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661



















































































































































































































































































































































































































































































































































































































































































                                                                                                   
Building and Installing Erlang/OTP
==================================

Please read the whole file before attempting to build and install Erlang/OTP.
You can find more information about Open Source Erlang/OTP at:

   <http://www.erlang.org/>

The source code for Erlang/OTP can also be found in a Git repository:

   <http://github.com/erlang/otp>

Portability
-----------

Erlang/OTP should be possible to build from source on any Unix system,
including Mac OS X. This document describes how to native compile Erlang/OTP
on Unix. For detailed instructions on how to

*   cross compile Erlang/OTP, see the [`$ERL_TOP/INSTALL-CROSS.md`] [1]
    document.

*   build Erlang/OTP on Windows, see the [`$ERL_TOP/INSTALL-WIN32.md`] [2]
    document.

    Binary releases for Windows can be found at
    <http://www.erlang.org/download.html>.

However, you are in any case advised to read this document first, since it
covers building Erlang/OTP in general as well as other important information.

Daily Build and Test
--------------------
At Ericsson we have a "Daily Build and Test" that runs on:

*   Solaris 8, 9
    *   Sparc32
    *   Sparc64
*   Solaris 10
    *   Sparc32
    *   Sparc64
    *   x86
*   SuSE Linux/GNU 9.4, 10.1
    *   x86
*   SuSE Linux/GNU 10.0, 10.1
    *   x86
    *   x86_64
*   SuSE Linux/GNU 11.0
    *   x86_64
*   Gentoo Linux/GNU 1.12.11.1
    *   x86
*   MontaVista Linux/GNU 4.0.1
    *   PowerPC
*   FreeBSD 7.1
    *   x86
*   Mac OS X 10.4.11 (Tiger), 10.5.8 (Leopard), 10.6.0 (Snow Leopard)
    *   x86
*   Windows XP SP3, 2003, Vista, 7
    *   x86

We also have the following "Daily Cross Builds":

*   SuSE Linux/GNU 10.1 x86 -> SuSE Linux/GNU 10.1 x86_64
*   SuSE Linux/GNU 10.1 x86_64 -> Linux/GNU TILEPro64

and the following "Daily Cross Build Tests":

*   SuSE Linux/GNU 10.1 x86_64

Versions Known *not* to Work
----------------------------

*   Suse linux 9.1 is shipped with a patched GCC version 3.3.3, having the
    rpm named `gcc-3.3.3-41`. That version has a serious optimization bug
    that makes it unusable for building the Erlang emulator. Please
    upgrade GCC to a newer version before building on Suse 9.1. Suse Linux
    Enterprise edition 9 (SLES9) has `gcc-3.3.3-43` and is not affected.

*   `gcc-4.3.0` has a serious optimizer bug. It produces an Erlang emulator
    that will crash immediately. The bug is supposed to be fixed in
    `gcc-4.3.1`.

*   FreeBSD had a bug which caused `kqueue`/`poll`/`select` to fail to detect
    that a `writev()` on a pipe has been made. This bug should have been fixed
    in FreeBSD 6.3 and FreeBSD 7.0. NetBSD and DragonFlyBSD probably have or
    have had the same bug. More information can be found at:

    *   <http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/sys_pipe.c>
    *   <http://lists.freebsd.org/pipermail/freebsd-arch/2007-September/006790.html>

*   `getcwd()` on Solaris 9 can cause an emulator crash. If you have
    async-threads enabled you can increase the stack size of the
    async-threads as a temporary workaround. See the `+a` command-line
    argument in the documentation of `erl(1)`. Without async-threads the
    emulator is not as vulnerable to this bug, but if you hit it without
    async-threads the only workaround available is to enable async-threads
    and increase the stack size of the async-threads. Sun has however
    released patches that fixes the issue:

    > Problem Description: 6448300 large mnttab can cause stack overrun
    > during Solaris 9 getcwd

    More information can be found at:

    *   <http://sunsolve.sun.com/search/document.do?assetkey=1-21-112874-40-1&searchclause=6448300>
    *   <http://sunsolve.sun.com/search/document.do?assetkey=1-21-114432-29-1&searchclause=6448300>

Required Utilities
------------------

These are the tools you will need in order to unpack and build Erlang/OTP.

### Unpacking ###

*   GNU unzip, or a modern uncompress.
*   A TAR program that understands the GNU TAR format for long filenames
    (such as GNU TAR).

### Building ###

*   GNU make
*   GNU C compiler
*   Perl 5
*   GNU m4 -- If hipe (native code) support is enabled.
*   ncurses (or termcap or termlib) -- The development headers and libraries
    are needed, often known as ncurses-devel. (Use --without-termcap to build
    without any of these libraries. Only the old shell (without any line
    editing) can be used.)
*   OpenSSL -- Optional, but needed for building the Erlang/OTP applications
    `ssl` and `crypto`. You need the "development package" of OpenSSL, i.e.
    including the header files. For building the application `ssl` the OpenSSL
    binary command program `openssl` is also needed.
    At least version 0.9.7 of OpenSSL is required.
*   Sun Java jdk-1.5.0 or higher -- Optional but needed for building the
    Erlang/OTP application `jinterface` and parts of `ic` and `orber`. We
    have also tested IBM's JDK 1.5.0.
*   X Windows -- Optional, but development headers and libraries are needed
    to build the Erlang/OTP application `gs` on Unix/Linux.
*  `sed` -- There seem to be some problems with some of the `sed` version on
    Solaris. Make sure `/bin/sed` or `/usr/bin/sed` is used on the Solaris
    platform.
*   Flex -- Optional, headers and libraries are needed to build the flex
    scanner for the `megaco` application on Unix/Linux.

If you are building in a Git working directory you also have to have a GNU
`autoconf` of at least version 2.59. Autoconf is however not needed if you
build an unmodified version of the released source.

### Installing ###

*   An `install` program that can take multiple file names.

How to Build and Install Erlang/OTP
-----------------------------------

The following instructions are for building using the source tar ball.

The variable `$ERL_TOP` will be mentioned a lot of times. It refers to
the top directory in the source tree. More information about `$ERL_TOP`
can be found in the "`make` and `$ERL_TOP`" section below. If you are
building in git you probably want to take a look at the "Building in Git"
section below before proceeding.

### Unpacking ###

Step 1: Start by unpacking the Erlang/OTP distribution file with your GNU
compatible TAR program.

    $ gunzip -c otp_src_R13B04.tar.gz | tar xf -
    $ zcat otp_src_R13B04.tar.gz | tar xf -


Step 2: Now cd into the base directory (`$ERL_TOP`).

    $ cd otp_src_R13B04

### Configuring ###

Step 3: On some platforms Perl may behave strangely if certain locales are
set, so optionally you may need to set the LANG variable:

    # Bourne shell
    $ LANG=C; export LANG

or

    # C-Shell
    $ setenv LANG C

Step 4: Run the following commands to configure the build:

    $ ./configure  [ options ]

By default, Erlang/OTP will be installed in `/usr/local/{bin,lib/erlang,man/man1}`.
To instead install in `<BaseDir>/{bin,lib/erlang,man/man1}`, use the
`--prefix=<BaseDir>` option.

If you upgraded the source with some patch you may need to clean up
from previous builds before the new build. Do a `make clean`; see
"Caveats" below.

### Building ###

Step 5: Build the Erlang/OTP package.

    $ make

### Installing ###

Step 6: Install then Erlang/OTP package

    $ make install

### A Closer Look at the individual Steps ###

Let us go through them in some detail.

#### Configuring ####

Step 4 runs a configuration script created by the GNU autoconf utility, which
checks for system specific features and then creates a number of makefiles.

The configure script allows you to customize a number of parameters;
type `./configure --help` or `./configure --help=recursive` for details.
`./configure --help=recursive` will give help for all `configure` scripts in
all applications.

One of the things you can specify is where Erlang/OTP should be installed: by
default Erlang/OTP will be installed in `/usr/local/{bin,lib/erlang,man/man1}`;
to keep the same structure but install in a different place, `<Dir>` say,
use the `--prefix` argument like this: `./configure --prefix=<Dir>`.

Some of the available `configure` options are:

  * `--prefix=PATH`: Specify installation prefix.
  * `--{enable,disable}-threads`: Thread support (enabled by default if
    possible)
  * `--{enable,disable}-smp-support`: SMP support (enabled by default if
    possible)
  * `--{enable,disable}-kernel-poll`: Kernel poll support (enabled by default
    if possible)
  * `--{enable,disable}-hipe`: HiPE support (enabled by default on supported
    platforms)
  * `--disable-erlang-mandir`: No private Erlang mandir, i.e., the common
    mandir under `--prefix`, or `--mandir` will be used
  * `--enable-darwin-universal`: Build universal binaries on darwin i386.
  * `--enable-darwin-64bit`: Build 64bit binaries on darwin
  * `--enable-m64-build`: Build 64bit binaries using the -m64 flag to (g)cc
  * `--enable-m32-build`: Build 32bit binaries using the -m32 flag to (g)cc
  * `--{with,without}-termcap`: termcap (without implies that only the old
    Erlang shell can be used)
  * `--with-javac=JAVAC`: Specify Java compiler to use
  * `--{with,without}-javac`: Java compiler (without implies that the
    `jinterface` application won't be built).
  * `--{enable,disable}-dynamic-ssl-lib`: Dynamic OpenSSL libraries
  * `--{enable,disable}-shared-zlib`: Shared zlib library
  * `--with-ssl=PATH`: Specify location of OpenSSL include and lib
  * `--{with,without}-ssl`: OpenSSL (without implies that the `crypto`, `ssh`,
    and `ssl` won't be built)

If you or your system has special requirements please read the
Makefile for additional configuration information.

#### Building ####

Step 5 builds the Erlang/OTP system. On a fast computer, this will take about
5 minutes. After completion of this step, you should have a working
Erlang/OTP system which you can try by typing `bin/erl`. This should start
up Erlang/OTP and give you a prompt.

#### Installing ####

Step 6 is optional. It installs Erlang/OTP at a standardized location (if you
change your mind about where you wish to install you can rerun step 4,
without having to do step 5 again).

##### Alternative Installation Procedures #####

*   Staged install using [`DESTDIR`] [3]. You can perform the install
    phase in a temporary directory and later move the installation into
    its correct location by use of the `DESTDIR` variable:

        $ make DESTDIR=<tmp install dir> install

    The installation will be created in a location prefixed by `$DESTDIR`.
    It can, however, not be run from there. It needs to be moved into the
    correct location before it can be run. If `DESTDIR` have not been set
    but `INSTALL_PREFIX` has been set, `DESTDIR` will be set to
    `INSTALL_PREFIX`. Note that `INSTALL_PREFIX` in pre R13B04 was buggy
    and behaved as `EXTRA_PREFIX` (see below). There are lots of areas of
    use for an installation procedure using `DESTDIR`, e.g. when creating
    a package, cross compiling, etc. Here is an example where the
    installation should be located under `/opt/local`:

        $ ./configure --prefix=/opt/local
        $ make
        $ make DESTDIR=/tmp/erlang-build install
        $ cd /tmp/erlang-build/opt/local
        $     # gnu-tar is used in this example
        $ tar -zcf /home/me/my-erlang-build.tgz *
        $ su -
        Password: *****
        $ cd /opt/local
        $ tar -zxf /home/me/my-erlang-build.tgz

*   Install using the `release` target. Instead of doing `make install` you
    can create the installation in whatever directory you like using the
    `release` target and run the `Install` script yourself. `RELEASE_ROOT`
    is used for specifying the directory where the installation should be
    created. This is what by default ends up under `/usr/local/lib/erlang`
    if you do the install using `make install`. All installation paths
    provided in the `configure` phase are ignored, as well as `DESTDIR`,
    and `INSTALL_PREFIX`. If you want links from a specific `bin` directory
    to the installation you have to set those up yourself. An example where
    Erlang/OTP should be located at `/home/me/OTP`:

        $ ./configure
        $ make
        $ make RELEASE_ROOT=/home/me/OTP release
        $ cd /home/me/OTP
        $ ./Install -minimal /home/me/OTP
        $ mkdir -p /home/me/bin
        $ cd /home/me/bin
        $ ln -s /home/me/OTP/bin/erl erl
        $ ln -s /home/me/OTP/bin/erlc erlc
        $ ln -s /home/me/OTP/bin/escript escript
        ...

    The `Install` script should currently be invoked as follows in the
    directory where it resides (the top directory):

        $ ./Install [-cross] [-minimal|-sasl] <ERL_ROOT>

    where:

    *   `-minimal` Creates an installation that starts up a minimal amount
        of applications, i.e., only `kernel` and `stdlib` are started. The
        minimal system is normally enough, and is what `make install` uses.
    *   `-sasl` Creates an installation that also starts up the `sasl`
        application.
    *   `-cross` For cross compilation. Informs the install script that it
        is run on the build machine.
    *   `<ERL_ROOT>` - The absolute path to the Erlang installation to use
        at run time. This is often the same as the current working directory,
        but does not have to be. It can follow any other path through the
        file system to the same directory.

    If neither `-minimal`, nor `-sasl` is passed as argument you will be
    prompted.

*   Test install using `EXTRA_PREFIX`. The content of the `EXTRA_PREFIX`
    variable will prefix all installation paths when doing `make install`.
    Note that `EXTRA_PREFIX` is similar to `DESTDIR`, but it does *not* have
    the same effect as `DESTDIR`. The installation can and have to be run
    from the location specified by `EXTRA_PREFIX`. That is, it can be useful
    if you want to try the system out, running test suites, etc, before doing
    the real install without `EXTRA_PREFIX`.

### Symbolic Links in `--bindir` ###

When doing `make install` and the default installation prefix is used,
relative symbolic links will be created from `/usr/local/bin` to all public
Erlang/OTP executables in `/usr/local/lib/erlang/bin`. The installation phase
will try to create relative symbolic links as long as `--bindir` and the
Erlang bin directory, located under `--libdir`, both have `--exec-prefix` as
prefix. Where `--exec-prefix` defaults to `--prefix`. `--prefix`,
`--exec-prefix`, `--bindir`, and `--libdir` are all arguments that can be
passed to `configure`. One can force relative, or absolute links by passing
`BINDIR_SYMLINKS=relative|absolute` as arguments to `make` during the install
phase. Note that such a request might cause a failure if the request cannot
be satisfied.

### Building in Git ###

When building in a Git working directory you also have to have a GNU `autoconf`
of at least version 2.59 on your system. This since you need to generate the
`configure` scripts before you can start building.

The `configure` scripts are generated by invoking `./otp_build autoconf` in
the `$ERL_TOP` directory. The `configure` scripts also have to be regenerated
when a `configure.in` or `aclocal.m4` file has been modified. Note that when
checking out a branch a `configure.in` or `aclocal.m4` file may change
content, and you may therefore have to regenerate the `configure` scripts
when checking out a branch. Regenerated `configure` scripts imply that you
have to run `configure` and build again.

Note that running `./otp_build autoconf` is **not** needed when building an
unmodified version the released source.

Other useful information can be found at our github wiki:
<http://wiki.github.com/erlang/otp>

Pre-built Source Tree
---------------------

The source tree is delivered with a lot of platform independent
build results already pre-built. If you want to remove these pre-built
files, invoke `./otp_build remove_prebuilt_files` from the `$ERL_TOP`
directory. After you have done this, you can build exactly the same way
as before, but the build process will take a much longer time.

*NOTE*: Doing `make clean` in an arbitrary directory of the source tree,
may remove files needed for bootstrapping the build. Doing
`./otp_build save_bootstrap` from the `$ERL_TOP` directory before
doing `make clean` will ensure that it will be possible to build after
doing `make clean`. `./otp_build save_bootstrap` will be invoked
automatically when `make` is invoked from `$ERL_TOP` with either the
`clean` target, or the default target. It is also automatically invoked
if `./otp_build remove_prebuilt_files` is invoked.

`make` and `$ERL_TOP`
---------------------

All the makefiles in the entire directory tree use the environment
variable `ERL_TOP` to find the absolute path of the installation. The
`configure` script will figure this out and set it in the top level
Makefile (which, when building, it will pass on). However, when
developing it is sometimes convenient to be able to run make in a
subdirectory. To do this you must set the `ERL_TOP` variable
before you run make.

For example, assume your GNU make program is called `make` and you
want to rebuild the application `STDLIB`, then you could do:

    $ cd lib/stdlib; env ERL_TOP=<Dir> make

where `<Dir>` would be what you find `ERL_TOP` is set to in the top level
Makefile.

Support for SMP (Symmetric Multi Processing)
--------------------------------------------

An emulator with SMP support will be built by default on most platforms
if a usable POSIX thread library or native Windows threads is found.

You can force building of an SMP emulator, by using
`./configure --enable-smp-support`. However, if configure does not
automatically enable SMP support, the build is very likely to fail.

Use `./configure --disable-smp-support` if you for some reason do not
want to have the emulator with SMP support built.

If SMP support is enabled, support for threaded I/O will also be turned on
(also in the emulator without SMP support).

The `erl` command will automatically start the SMP emulator if the
computer has more than one logical processor. You can force a start
of the emulator with SMP support by passing `-smp enable` as
command line arguments to erl, and you can force a start of the
emulator without SMP support by passing `-smp disable`.

How to install the Erlang/OTP documentation
-------------------------------------------

For some graphical tools to find the on-line help you have to install
the HTML documentation on top of the installed OTP applications, i.e.

    $ cd <PrefixDir>/lib/erlang
    $ gunzip -c otp_html_R<XY>B-<Z>.tar.gz | tar xf -

For `erl -man <page>` to work the Unix manual pages have to be
installed in the same way, i.e.

    $ cd <PrefixDir>/lib/erlang
    $gunzip -c otp_man_R<XY>B-<Z>.tar.gz | tar xf -


GS (Graphic System)
-------------------

GS now Tcl/Tk 8.4. It will be searched for when starting GS.

Using HiPE
----------

HiPE supports the following system configurations:

*   x86: All 32-bit and 64-bit mode processors should work.

    *   Linux: Fedora Core is supported. Both 32-bit and 64-bit modes are
        supported.

        NPTL glibc is strongly preferred, or a LinuxThreads
        glibc configured for "floating stacks". Old non-floating
        stacks glibcs have a fundamental problem that makes HiPE
        support and threads support mutually exclusive.

    *   Solaris: Solaris 10 (32-bit and 64-bit) and 9 (32-bit) are supported.
        The build requires a version of the GNU C compiler (gcc)
        that has been configured to use the GNU assembler (gas).
        Sun's x86 assembler is emphatically **not** supported.

    *   FreeBSD: FreeBSD 6.1 and 6.2 in 32-bit and 64-bit modes should work.

    *   MacOSX/Darwin: Darwin 9.8.0 in 32-bit mode should work.

*   PowerPC: All 32-bit 6xx/7xx(G3)/74xx(G4) processors should work. 32-bit
    mode on 970 (G5) and POWER5 processors should work.

    * Linux (Yellow Dog) and Mac OSX 10.4 are supported.

*   SPARC: All UltraSPARC processors running 32-bit user code should work.

    *   Solaris 9 is supported. The build requires a `gcc` that has been
        configured to use Sun's assembler and linker. Using the GNU assembler
        but Sun's linker has been known to cause problems.

    *   Linux (Aurora) is supported.

*   ARM: ARMv5TE (i.e. XScale) processors should work. Both big-endian and
    little-endian modes are supported.

    * Linux is supported.

HiPE is automatically enabled on the following systems:

*   x86 in 32-bit mode: Linux, Solaris, FreeBSD
*   x86 in 64-bit mode: Linux, Solaris, FreeBSD
*   PowerPC: Linux, MacOSX
*   SPARC: Linux
*   ARM: Linux

On other supported systems you need to `./configure --enable-hipe`.

If you are running on a platform supporting HiPE and if you have not disabled
HiPE, you can compile a module into native code like this from the Erlang
shell:

    1> c(Module, native).

or

    1> c(Module, [native|OtherOptions]).

Using the erlc program, write like this:

    $ erlc +native Module.erl

The native code will be placed into the beam file and automatically loaded
when the beam file is loaded.

To add hipe options, write like this from the Erlang shell:

    1> c(Module, [native,{hipe,HipeOptions}|MoreOptions]).

Use hipe:help_options/0 to print out the available options.

    1> hipe:help_options().

Mac OS X (Darwin)
-----------------

We test Mac OS X 10.4.11 (Tiger) and Mac OS X 10.5.x (Leopard) in our daily
builds (but only on Intel processors).

Make sure that the command `hostname` returns a valid fully qualified host
name (this is configured in `/etc/hostconfig`).

If you develop linked-in drivers (shared library) you need to link using
`gcc` and the flags `-bundle -flat_namespace -undefined suppress`. You also
include `-fno-common` in `CFLAGS` when compiling. Use `.so` as the library
suffix.

Universal 32bit binaries can be built on an Intel Mac using the
`--enable-darwin-universal` configure option. There still may occur
problems with certain applications using this option, but the base
system should run smoothly.

When building universal binaries on a PowerPC Mac (at least on Tiger),
you must point out a suitable SDK that contains universal binaries.
For instance, to build universal binaries for Tiger (10.4):

    $ CFLAGS="-isysroot /Developer/SDKs/MacOSX10.4u.sdk" \
    LDFLAGS="-isysroot /Developer/SDKs/MacOSX10.4u.sdk" \
    ./configure --enable-darwin-universal

Also, if you run Leopard, but want to build for Tiger, you must do by
setting the `MACOSX_DEPLOYMENT_TARGET` environmental variable.

    $ export MACOSX_DEPLOYMENT_TARGET=10.4

Experimental support for 64bit x86 darwin binaries can be enabled
using the `--enable-darwin-64bit` configure flag. The 64bit binaries are
best built and run on Leopard, but most of the system also works on
Tiger (Tiger's 64bit libraries are, however, limited; therefore e.g. `odbc`,
`crypto`, `ssl` etc. are not supported in Tiger). 64bit PPC binaries are not
supported and we have no plans to add such support (no machines to
test on).

Universal binaries and 64bit binaries are mutually exclusive options.

How to Build a Debug Enabled Erlang RunTime System
--------------------------------------------------

After completing all the normal building steps described above a debug
enabled runtime system can be built. To do this you have to change
directory to `$ERL_TOP/erts/emulator`.

In this directory execute:

    $ make debug FLAVOR=$FLAVOR

where `$FLAVOR` is either `plain` or `smp`. The flavor options will
produce a beam.debug and beam.smp.debug executable respectively. The
files are installed along side with the normal (opt) versions `beam.smp`
and `beam`.

To start the debug enabled runtime system execute:

    $ $ERL_TOP/bin/cerl -debug

The debug enabled runtime system features lock violation checking,
assert checking and various sanity checks to help a developer ensure
correctness. Some of these features can be enabled on a normal beam
using appropriate configure options.

There are other types of runtime systems that can be built as well
using the similar steps just described.

    $ make $TYPE FLAVOR=$FLAVOR

where `$TYPE` is `opt`, `gcov`, `gprof`, `debug`, `valgrind`, or `lcnt`.
These different beam types are useful for debugging and profiling
purposes.

Authors
-------
Authors are mostly listed in the application's `AUTHORS` files,
that is `$ERL_TOP/lib/*/AUTHORS` and `$ERL_TOP/erts/AUTHORS`,
not in the individual source files.

Copyright and License
---------------------

> %CopyrightBegin%
>
> Copyright Ericsson AB 1998-2010. All Rights Reserved.
>
> The contents of this file are subject to the Erlang Public License,
> Version 1.1, (the "License"); you may not use this file except in
> compliance with the License. You should have received a copy of the
> Erlang Public License along with this software. If not, it can be
> retrieved online at http://www.erlang.org/.
>
> Software distributed under the License is distributed on an "AS IS"
> basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
> the License for the specific language governing rights and limitations
> under the License.
>
> %CopyrightEnd%

More Information
----------------

More information can be found at <http://www.erlang.org>.



   [1]: INSTALL-CROSS.html "$ERL_TOP/INSTALL-CROSS.md"
   [2]: INSTALL-WIN32.html "$ERL_TOP/INSTALL-WIN32.md"
   [3]: http://www.gnu.org/prep/standards/html_node/DESTDIR.html "DESTDIR"