distcc - distributed C/C++/ObjC compiler with distcc-pump extensions
distcc <compiler> [COMPILER OPTIONS]
distcc [COMPILER OPTIONS]
<compiler> [COMPILER OPTIONS]
distcc [DISTCC OPTIONS]
distcc distributes compilation of C code across several machines on a network.
distcc should always generate the same results as a local compile, it is
simple to install and use, and it is often much faster than a local compile.
This version incorporates plain distcc as well as an enhancement called pump
mode or distcc-pump.
For each job, distcc in plain mode sends the complete preprocessed source code
and compiler arguments across the network from the client to a compilation
server. In pump mode, distcc sends the source code and recursively included
header files (excluding those from the default system header directories), so
that both preprocessing and compilation can take place on the compilation
servers. This speeds up the delivery of compilations by up to an order of
magnitude over plain distcc.
Compilation is driven by a client machine, which is typically the developer's
workstation or laptop. The distcc client runs on this machine, as does make,
the preprocessor (if distcc's pump mode is not used), the linker, and other
stages of the build process. Any number of volunteer machines act as
compilation servers and help the client to build the program, by running the
daemon, C compiler and assembler as required.
distcc can run across either TCP sockets (on port 3632 by default), or through a
tunnel command such as ssh(1). For TCP connections the volunteers must run the
distccd(1) daemon either directly or from inetd. For SSH connections distccd
must be installed but should not
be listening for connections.
TCP connections should only be used on secure networks because there is no user
authentication or protection of source or object code. SSH connections are
distcc is intended to be used with GNU Make's -j
option, which runs
several compiler processes concurrently. distcc spreads the jobs across both
local and remote CPUs. Because distcc is able to distribute most of the work
across the network, a higher concurrency level can be used than for local
builds. As a rule of thumb, the -j
value should be set to about twice
the total number of available server CPUs but subject to client limitations.
This setting allows for maximal interleaving of tasks being blocked waiting
for disk or network IO. Note that distcc can also work with other build
control tools, such as SCons, where similar concurrency settings must be
setting, especially for large values of -j,
must take into
account the CPU load on the client. Additional measures may be needed to
curtail the client load. For example, concurrent linking should be severely
curtailed using auxiliary locks. The effect of other build activity, such as
Java compilation when building mixed code, should be considered. The
parameter is by default set to 8. This limits the
number of concurrent processes that do preprocessing in plain distcc
(non-pump) mode. Therefore, larger -j
values than 8 may be used without
overloading a single-CPU client due to preprocessing. Such large values may
speed up parts of the build that do not involve C compilations, but they may
not be useful to distcc efficiency in plain mode.
In contrast, using pump mode and say 40 servers, a setting of -j80
larger may be appropriate even for single-CPU clients.
It is strongly recommended that you install the same compiler version on all
machines participating in a build. Incompatible compilers may cause mysterious
compile or link failures.
- For each machine, download distcc, unpack, and install.
- On each of the servers, run distccd --daemon with --allow
options to restrict access.
- Put the names of the servers in your environment:
$ export DISTCC_HOSTS='localhost red green blue'
$ make -j8 CC=distcc
Proceed as above, but in Step 3, specify that the remote hosts are to carry the
burden of preprocessing and that the files sent over the network should be
$ export DISTCC_HOSTS='--randomize localhost red,cpp,lzo
option enforces a uniform usage of compile servers. While
you will get some benefit from distcc's pump mode with only a few servers, you
get increasing benefit with more server CPUs (up to the hundreds!). Wrap your
build inside the pump command, here assuming 10 servers:
$ pump make -j20 CC=distcc
Proceed as per the QUICKSTART
but in Step 3, specify that the remote
hosts are to mutually authenticate with the client:
$ export DISTCC_HOSTS='--randomize localhost red,auth
If distccd runs under a specific principal name then execute the following
command prior to step 4:
distcc only ever runs the compiler and assembler remotely. With plain distcc,
the preprocessor must always run locally because it needs to access various
header files on the local machine which may not be present, or may not be the
same, on the volunteer. The linker similarly needs to examine libraries and
object files, and so must run locally.
The compiler and assembler take only a single input file (the preprocessed
source) and produce a single output (the object file). distcc ships these two
files across the network and can therefore run the compiler/assembler
Fortunately, for most programs running the preprocessor is relatively cheap, and
the linker is called relatively infrequent, so most of the work can be
distcc examines its command line to determine which of these phases are being
invoked, and whether the job can be distributed.
In pump mode, distcc runs the preprocessor remotely too. To do so, the
preprocessor must have access to all the files that it would have accessed if
had been running locally. In pump mode, therefore, distcc gathers all of the
recursively included headers, except the ones that are default system headers,
and sends them along with the source file to the compilation server.
In distcc-pump mode, the server unpacks the set of all source files in a
temporary directory, which contains a directory tree that mirrors the part of
the file system that is relevant to preprocessing, including symbolic links.
The compiler is then run from the path in the temporary directory that
corresponds to the current working directory on the client. To find and
transmit the many hundreds of files that are often part of a single
compilation, pump mode uses an incremental include analysis algorithm. The
include server is a Python program that implements this algorithm. The pump
command starts the include server so that throughout the build it can answer
include queries by distcc commands.
The include server uses static analysis of the macro language to deal with
conditional compilation and computed includes. It uses the property that when
a given header file has already been analyzed for includes, it is not
necessary to do so again if all the include options (-I's) are unchanged
(along with other conditions).
For large builds, header files are included, on average, hundreds of times each.
With distcc-pump mode each such file is analyzed only a few times, perhaps
just once, instead of being preprocessed hundreds of times. Also, each source
or header file is now compressed only once, because the include server
memoizes the compressed files. As a result, the time used for preparing
compilations may drop by up to an order of magnitude over the preprocessing of
Because distcc in pump mode is able to push out files up to about ten times
faster, build speed may increase 3X or more for large builds compared to plain
Using pump mode requires both client and servers to use release 3.0 or later of
distcc and distccd (respectively).
The incremental include analysis of distc-pump mode rests on the fundamental
assumption that source and header files do not change during the build
process. A few complex build systems, such as that for Linux kernel 2.6, do
not quite satisfy this requirement. To overcome such issues, and other corner
cases such as absolute filepaths in includes, see the include_server(1)
Another important assumption is that the include configuration of all machines
must be identical. Thus the headers under the default system path must be the
same on all servers and all clients. If a standard GNU compiler installation
is used, then this requirement applies to all libraries whose header files are
installed under /usr/include or /usr/local/include/. Note that installing
software packages often lead to additional headers files being placed in
subdirectories of either.
If this assumption does not hold, then it is possible to break builds with
distcc-pump mode, or worse, to get wrong results without warning. Presently
this condition is not verified, and it is on our TODO list to address this
An easy way to guarantee that the include configurations are identical is to use
a cross-compiler that defines a default system search path restricted to
directories of the compiler installation.
See the include_server(1)
manual for more information on symptoms and
causes of violations of distcc-pump mode assumptions.
In this mode distcc will use the GSS-API framework to access the currently
configured security mechanism and perform mutual authentication with the
Most options passed to distcc are interpreted as compiler options. The following
options are understood by distcc itself. If any of these options are
specified, distcc will not invoke the compiler.
- Displays summary instructions.
- Displays the distcc client version.
- Displays the host list that distcc would use. See the Host Specifications
- Displays the list of files that distcc would send to the remote machine,
as computed by the include server. This is a conservative
(over-)approximation of the files that would be read by the C compiler.
This option only works in pump mode. See the "How Distcc-pump Mode
Works" section for details on how this is computed.
The list output by distcc --scan-includes
will contain one entry per
line. Each line contains a category followed by a path. The category is one of
FILE, SYMLINK, DIRECTORY, or SYSTEMDIR:
- FILE indicates a source file or header file that would be sent to
the distcc server host.
- SYMLINK indicates a symbolic link that would be sent to the distcc
- DIRECTORY indicates a directory that may be needed in order to
compile the source file. For example, a directory "foo" may be
needed because of an include of the form #include
"foo/../bar.h". Such directories would be created on the distcc
- SYSTEMDIR indicates a system include directory, i.e. a directory
which is on the compiler's default include path, such as
"/usr/include"; such directories are assumed to be present on
the distcc server host, and so would not be sent to the distcc server
- Displays distcc's concurrency level, as calculated from the host list; it
is the maximum number of outstanding jobs issued by this client to all
servers. By default this will be four times the number of hosts in the
host list, unless the /LIMIT option was used in the host list. See the
Host Specifications section.
- Displays the name of the distccd security principal extracted from the
environment. This option is only available if distcc was compiled
with the --with-auth configure option.
There are three different ways to call distcc, to suit different circumstances:
distcc can be installed under the name of the real compiler, to intercept calls
to it and run them remotely. This "masqueraded" compiler has the
widest compatibility with existing source trees, and is convenient when you
want to use distcc for all compilation. The fact that distcc is being used is
transparent to the makefiles.
distcc can be prepended to compiler command lines, such as "distcc cc -c
hello.c" or CC="distcc gcc". This is convenient when you want
to use distcc for only some compilations or to try it out, but can cause
trouble with some makefiles or versions of libtool that assume $CC does not
contain a space.
Finally, distcc can be used directly as a compiler. "cc" is always
used as the name of the real compiler in this "implicit" mode. This
can be convenient for interactive use when "explicit" mode does not
work but is not really recommended for new use.
Remember that you should not use two methods for calling distcc at the same
time. If you are using a masquerade directory, don't change CC and/or CXX,
just put the directory early on your PATH. If you're not using a masquerade
directory, you'll need to either change CC and/or CXX, or modify the
makefile(s) to call distcc explicitly.
The basic idea is to create a "masquerade directory" which contains
links from the name of the real compiler to the distcc binary. This directory
is inserted early on the PATH, so that calls to the compiler are intercepted
and distcc is run instead. distcc then removes itself from the PATH to find
the real compiler.
# mkdir /usr/lib/distcc/bin
# cd /usr/lib/distcc/bin
# ln -s ../../../bin/distcc gcc
# ln -s ../../../bin/distcc cc
# ln -s ../../../bin/distcc g++
# ln -s ../../../bin/distcc c++
Then, to use distcc, a user just needs to put the directory /usr/lib/distcc/bin
early in the PATH, and have set a host list in DISTCC_HOSTS or a file. distcc
will handle the rest.
To automatically discover compilers and create masquerade links run the provided
Note that this masquerade directory must occur on the PATH earlier than the
directory that contains the actual compilers of the same names, and that any
auxiliary programs that these compilers call (such as as or ld) must also be
found on the PATH in a directory after the masquerade directory since distcc
calls out to the real compiler with a PATH value that has all directory up to
and including the masquerade directory trimmed off.
It is possible to get a "recursion error" in masquerade mode, which
means that distcc is somehow finding itself again, not the real compiler. This
can indicate that you have two masquerade directories on the PATH, possibly
because of having two distcc installations in different locations. It can also
indicate that you're trying to mix "masqueraded" and
Recursion errors can be avoided by using shell scripts instead of links. For
example, in /usr/lib/distcc/bin create a file cc which contains:
distcc /usr/bin/gcc "$@"
In this way, we are not dependent on distcc having to locate the real gcc by
investigating the PATH variable. Instead, the compiler location is explicitly
ccache is a program that speeds software builds by caching the results of
compilations. ccache is normally called before distcc, so that results are
retrieved from a normal cache. Some experimentation may be required for
idiosyncratic makefiles to make everything work together.
The most reliable method is to set
This tells ccache to run distcc as a wrapper around the real compiler. ccache
still uses the real compiler to detect compiler upgrades.
ccache can then be run using either a masquerade directory or
- CC="ccache gcc"
As of version 2.2, ccache does not cache compilation from preprocessed source
and so will never get a cache hit if it is run from distccd or distcc. It must
be run only on the client side and before distcc to be any use.
distcc's pump mode is not compatible with ccache.
A "host list" tells distcc which machines to use for compilation. In
order, distcc looks in the $DISTCC_HOSTS
environment variable, the
file, and the system-wide host file. If no
host list can be found, distcc emits a warning and compiles locally.
The host list is a simple whitespace separated list of host specifications. The
simplest and most common form is a host names, such as
localhost red green blue
distcc prefers hosts towards the start of the list, so machines should be listed
in descending order of speed. In particular, when only a single compilation
can be run (such as from a configure script), the first machine listed is used
(but see --randomize
at the right point in the list is important to getting
good performance. Because overhead for running jobs locally is low, localhost
should normally be first. However, it is important that the client have enough
cycles free to run the local jobs and the distcc client. If the client is
slower than the volunteers, or if there are many volunteers, then the client
should be put later in the list or not at all. As a general rule, if the
aggregate CPU speed of the client is less than one fifth of the total, then
the client should be left out of the list.
If you have a large shared build cluster and a single shared hosts file, the
above rules would cause the first few machines in the hosts file to be tried
first even though they are likely to be busier than machines later in the
list. To avoid this, place the keyword --randomize
into the host list.
This will cause the host list to be randomized, which should improve
performance slightly for large build clusters.
There are two special host names --localslots
which are useful for adjusting load on the local machine. The
host specifies how many jobs that cannot be run remotely
that can be run concurrently on the local machine, while
controls how many preprocessors will run in parallel
on the local machine. Tuning these values can improve performance. Linking on
large projects can take large amounts of memory. Running parallel linkers,
which cannot be executed remotely, may force the machine to swap, which
reduces performance over just running the jobs in sequence without swapping.
Getting the number of parallel preprocessors just right allows you to use
larger parallel factors with make, since the local machine now has some
machanism for measuring local resource usage.
Finally there is the host entry
Performance depends on the details of the source and makefiles used for the
project, and the machine and network speeds. Experimenting with different
settings for the host list and -j
factor may improve performance.
The syntax is
DISTCC_HOSTS = HOSTSPEC ...
HOSTSPEC = LOCAL_HOST | SSH_HOST | TCP_HOST | OLDSTYLE_TCP_HOST
LOCAL_HOST = localhost[/LIMIT]
SSH_HOST = [USER]@HOSTID[/LIMIT][:COMMAND][OPTIONS]
TCP_HOST = HOSTID[:PORT][/LIMIT][OPTIONS]
OLDSTYLE_TCP_HOST = HOSTID[/LIMIT][:PORT][OPTIONS]
HOSTID = HOSTNAME | IPV4 | IPV6
OPTIONS = ,OPTION[OPTIONS]
OPTION = lzo | cpp | auth
GLOBAL_OPTION = --randomize
ZEROCONF = +zeroconf
Here are some individual examples of the syntax:
- The literal word "localhost" is interpreted specially to cause
compilations to be directly executed, rather than passed to a daemon on
the local machine. If you do want to connect to a daemon on the local
machine for testing, then give the machine's IP address or real hostname.
(This will be slower.)
- A literal IPv6 address enclosed in square brackets, such as
- A literal IPv4 address, such as 10.0.0.1
- A hostname to be looked up using the resolver.
- Connect to a specified decimal port number, rather than the default of
- Connect to the host over SSH, rather than TCP. Options for the SSH
connection can be set in ~/.ssh/config
- Connect to the host over SSH as a specified username.
- Connect over SSH, and use a specified path to find the distccd server.
This is normally only needed if for some reason you can't install distccd
into a directory on the default PATH for SSH connections. Use this if you
get errors like "distccd: command not found" in SSH mode.
- A decimal limit can be added to any host specification to restrict the
number of jobs that this client will send to the machine. The limit
defaults to four per host (two for localhost), but may be further
restricted by the server. You should only need to increase this for
servers with more than two processors.
- Enables LZO compression for this TCP or SSH host.
- Enables distcc-pump mode for this host. Note: the build command must be
wrapped in the pump script in order to start the include server.
- Enables GSSAPI-based mutual authentication for this host.
- Randomize the order of the host list before execution.
- This option is only available if distcc was compiled with Avahi support
enabled at configure time. When this special entry is present in the
hosts list, distcc will use Avahi Zeroconf DNS Service Discovery (DNS-SD)
to locate any available distccd servers on the local network. This avoids
the need to explicitly list the host names or IP addresses of the distcc
server machines. The distccd servers must have been started with the
"--zeroconf" option to distccd. An important caveat is that in
the current implementation, pump mode (",cpp") and compression
(",lzo") will never be used for hosts located via zeroconf.
Here is an example demonstrating some possibilities:
localhost/2 @bigman/16:/opt/bin/distccd oldmachine:4200/1
# cartman is down
Comments are allowed in host specifications. Comments start with a hash/pound
sign ( #
) and run to the end of the line.
If a host in the list is not reachable distcc will emit a warning and ignore
that host for about one minute.
host option specifies that LZO compression should be used for
data transfer, including preprocessed source, object code and error messages.
Compression is usually economical on networks slower than 100Mbps, but results
may vary depending on the network, processors and source tree.
Enabling compression makes the distcc client and server use more CPU time, but
less network traffic. The added CPU time is insignificant for pump mode. The
compression ratio is typically 4:1 for source and 2:1 for object code.
Using compression requires both client and server to use at least release 2.9 of
distcc. No server configuration is required: the server always responds with
compressed replies to compressed requests.
Pump mode requires the servers to have the lzo host option on.
If the compiler name is an absolute path, it is passed verbatim to the server
and the compiler is run from that directory. For example:
distcc /usr/local/bin/gcc-3.1415 -c hello.c
If the compiler name is not absolute, or not fully qualified, distccd's PATH is
searched. When distcc is run from a masquerade directory, only the base name
of the compiler is used. The client's PATH is used only to run the
preprocessor and has no effect on the server's path.
Both the distcc client and server impose timeouts on transfer of data across the
network. This is intended to detect hosts which are down or unreachable, and
to prevent compiles hanging indefinitely if a server is disconnected while in
use. If a client-side timeout expires, the job will be re-run locally.
The transfer timeout is not configurable at present. The timeout that detects
stale distributed job is configurable via DISTCC_IO_TIMEOUT environment
Error messages or warnings from local or remote compilers are passed through to
diagnostic output on the client.
distcc can supply extensive debugging information when the verbose option is
used. This is controlled by the DISTCC_VERBOSE
environment variable on
the client, and the --verbose
option on the server. For
troubleshooting, examine both the client and server error messages.
The exit code of distcc is normally that of the compiler: zero for successful
compilation and non-zero otherwise.
distcc distinguishes between "genuine" errors such as a syntax error
in the source, and "accidental" errors such as a networking problem
connecting to a volunteer. In the case of accidental errors, distcc will retry
the compilation locally unless the DISTCC_FALLBACK option has been disabled.
If the compiler exits with a signal, distcc returns an exit code of 128 plus the
distcc internal errors cause an exit code between 100 and 127. In particular
- General distcc failure.
- Bad arguments.
- Bind failed.
- Connect failed.
- Compiler crashed.
- Out of memory.
- Bad Host SPEC
- I/O Error
- Protocol Error.
- The given compiler was not found on the remote host. Check that $CC is set
appropriately and that it's installed in a directory on the search path
- Recursive call to distcc.
- Failed to discard privileges.
- Network access denied.
- In use by another process.
- No such file.
- No hosts defined and fallbacks disabled.
- GSS-API - Catchall error code for GSS-API related errors.
- Called for preprocessing, which needs to be done locally.
If $DISTCC_HOSTS is not set, distcc reads a host list from either
or a system-wide configuration file set at compile
time. The file locations are shown in the output from distcc --help
distcc creates a number of temporary and lock files underneath the temporary
distcc's behaviour is controlled by a number of environment variables. For most
cases nothing need be set if the host list is stored in a file.
- Space-separated list of volunteer host specifications.
- If set to 1, distcc produces explanatory messages on the standard error
stream or in the log file. This can be helpful in debugging problems. Bug
reports should include verbose output.
- Log file to receive messages from distcc itself, rather than stderr.
- By default distcc will compile locally if it fails to distribute a job to
the intended machine, or if no host list can be found. If this variable is
set to 0 then fallbacks are disabled and those compilations will simply
fail. Note that this does not affect jobs which must always be local such
- By default distcc will rewrite calls gcc to use fully qualified names
(like x86_64-linux-gnu-gcc), and clang to use the -target option. Setting
this turns that off.
- Specifies how long (in seconds) distcc will avoid trying to use a
particular compilation server after that server yields a compile failure.
By default set to 60 seconds. To disable the backoff behavior altogether,
set this to 0.
- Specifies how long (in seconds) distcc will wait before deciding a
distributed job has timed out. If a distributed job is expected to takes a
long time, consider increasing this value so the job does not time out and
fallback to a local compile. By default set to 300 seconds.
- Specifies how long (in milliseconds) distcc will pause when all
compilation servers are in use. By default set to 1000 milliseconds (1
second). Setting this to a smaller value (e.g. 10 milliconds) may improve
throughput for some configurations, at the expense of increased CPU load
on the distcc client machine.
- If set to 1, temporary files are not deleted after use. Good for
debugging, or if your disks are too empty.
- If set to 0, disable use of "TCP corks", even if they're present
on this system. Using corks normally helps pack requests into fewer
packets and aids performance. This should normally be left enabled.
- Specifies the command used for opening SSH connections. Defaults to
"ssh" but may be set to a different connection command such as
"lsh" or "tsocks-ssh" that accepts a similar command
line. The command is not split into words and is not executed through the
- If set, when a remote compile fails, distcc will no longer try to
recompile that file locally.
- Per-user configuration directory to store lock files and state files. By
default ~/.distcc/ is used.
- Directory for temporary files such as preprocessor output. By default
/tmp/ is used.
- If set and if DISTCC_LOG is not set, distcc errors are written to the file
descriptor identified by this variable. This variable is intended mainly
for automatic use by ccache, which sets it to avoid caching transient
errors such as network problems.
- If set, distcc sends an email when a compilation failed remotely, but
succeeded locally. Built-in heuristics prevent some such discrepancy email
from being sent if the problem is that a local file changed between the
failing remote compilation and the succeeding local compilation.
- The maximum number of remote compilation failures allowed in pump mode
before distcc switches to plain distcc mode. By default set to 1.
- The email address for discrepancy email; the default is
- If set, specifies the name of the principal that distccd runs under, and
is used to authenticate the server to the client. This environment
variable is only used if distcc was compiled with the --with-auth
configure option and the ,auth per host option is specified.
Cross compilation means building programs to run on a machine with a different
processor, architecture, or operating system to where they were compiled.
distcc supports cross compilation, including teams of mixed-architecture
machines, although some changes to the compilation commands may be required.
The compilation command passed to distcc must be one that will execute properly
on every volunteer machine to produce an object file of the appropriate type.
If the machines have different processors, then simply using distcc cc
will probably not work, because that will normally invoke the volunteer's
Machines with the same CPU but different operating systems may not necessarily
generate compatible .o files.
Several different gcc configurations can be installed side-by-side on any
machine. If you build gcc from source, you should use the --program-suffix
options to cause it to be installed with a name that encodes
the gcc version and the target platform.
The recommended convention for the gcc name is TARGET-gcc-VERSION
. GCC 3.3 will install itself under this name, in
addition to TARGET-gcc
and, if it's native, gcc-VERSION
The compiler must be installed under the same name on the client and on every
If you think you have found a distcc bug, please see the file
in the documentation directory for information on
how to report it.
Some makefiles have missing or extra dependencies that cause incorrect or slow
parallel builds. Recursive make is inefficient and can leave processors
unnecessarily idle for long periods. (See Recursive Make Considered
by Peter Miller.) Makefile bugs are the most common cause of trees
failing to build under distcc. Alternatives to Make such as SCons
give much faster builds for some projects.
Using different versions of gcc can cause confusing build problems because the
header files and binary interfaces have changed over time, and some
distributors have included incompatible patches without changing the version
number. distcc does not protect against using incompatible versions. Compiler
errors about link problems or declarations in system header files are usually
due to mismatched or incorrectly installed compilers.
option can produce output in the wrong directory if the source
and object files are in different directories and the -MF
option is not
used. There is no perfect solution because of incompatible changes between gcc
versions. Explicitly specifying the dependency output file with -MF
will fix the problem.
TCP mode connections should only be used on trusted networks.
Including slow machines in the list of volunteer hosts can slow the build down.
When distcc or ccache is used on NFS, the filesystem must be exported with the
option to allow reliable renames between directories.
The compiler can be invoked with a command line gcc hello.c
compile and link. distcc doesn't split this into separate parts, but rather
runs the whole thing locally.
distcc-pump mode reverts to plain distcc mode for source files that contain
includes with absolute paths (either directly or in an included file).
Due to limitations in gcc, gdb may not be able to automatically find the source
files for programs built using distcc in some circumstances. The gdb
command can be used. For distcc's plain (non-pump) mode, this
is fixed in gcc 3.4 and later. For pump mode, the fix in gcc 3.4 does not
suffice; we've worked around the gcc limitation by rewriting the object files
that gcc produces, but this is only done for ELF object files, but not for
other object file formats.
The .o files produced by discc in pump mode will be different from those
produced locally: for non-ELF files, the debug information will specify
compile directories of the server. The code itself should be identical.
For the ELF-format, distcc rewrites the .o files to correct compile directory
path information. While the resulting .o files are not bytewise identical to
what would have been produced by compiling on the local client (due to
different padding, etc), they should be functionally identical.
In distcc-pump mode, the include server is unable to handle certain very
complicated computed includes as found in parts of the Boost library. The
include server will time out and distcc will revert to plain mode.
In distcc-pump mode, certain assumptions are made that source and header files
do not change during the build. See discussion in section DISTCC DISCREPANCY
SYMPTOMS of include_server
Other known bugs may be documented on http://code.google.com/p/distcc/
distcc was written by Martin Pool <email@example.com>, with the
co-operation of many scholars including Wayne Davison, Frerich Raabe, Dimitri
Papadopoulos and others noted in the NEWS file. Please report bugs to
<firstname.lastname@example.org>. See pump(1)
for the authors of pump
You are free to use distcc. distcc (including this manual) may be copied,
modified or distributed only under the terms of the GNU General Public Licence
version 2 or later. distcc comes with absolutely no warrany. A copy of the GPL
is included in the file COPYING.
, and ccache(1)