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Synth - Custom package repository builder for FreeBSD and DragonFly

Synth is an advanced concurrent (parallel) ports building tool aimed at regular users that prefer or require building their own packages from source. Synth will build packages in a clean environment that exactly mirrors the system it builds on, creates a local repository, installs a pkg repository configuration file that causes the local packages to be used with the highest priority, and automatically upgrades the system with a single command.

> synth version

The version screen appears when Synth is executed with no command, an unknown command, or the "version" command. It displays the current version, the copyright, and a summary of valid commands along with the usage.

  Custom package repository builder for FreeBSD and DragonFly 2.02
               Copyright (C) 2015-2017 John R. Marino

Usage: synth [zero-parameter-option]
-or-   synth [list-option] <list of port origins | filename>

zero-parameter-option includes: help, configure, version, status,
                      upgrade-system, prepare-system, status-everything
                      everything, purge-distfiles, rebuild-repository
list-option includes: status, build, just-build, install, force, test

> synth help

The help screen appears when "synth help" is entered from the command line. It provides a slightly longer explanation of each command Synth recognizes. For the most detailed explanation of the Synth commands, please refer the manual page, e.g. "man synth".

Summary of command line options - see synth.1 man page for more details
synth status              Dry-run: Shows what 'upgrade-system' would build
synth configure           Brings up interactive configuration menu
synth upgrade-system      Incremental rebuild of installed packages on system.
                          Afterwards, the local repository is rebuilt and the
                          system packages are automatically upgraded.
synth prepare-system      Like 'upgrade-system' but ends when repo is rebuilt
synth rebuild-repository  Rebuilds local Synth repository on command
synth purge-distfiles     Deletes obsolete source distribution files
synth status-everything   Dry-run: Shows what 'everything' would build
synth everything          Builds entire ports tree and rebuilds repository
synth version             Displays version, description and usage summary
synth help                Displays this screen
synth status [ports]      Dry-run: Shows what will be rebuilt with given list
synth build [ports]       Incrementally build ports based on given list, but
                          asks before updating repository and system
synth just-build [ports]  Like 'build', but skips post-build questions
synth install [ports]     Like 'build', but upgrades system without asking
synth force [ports]       Like 'build', but deletes existing packages first

synth test [ports]        Just builds with DEVELOPER=yes; pre-deletes pkgs

[ports] is a space-delimited list of origins, e.g. editors/joe editors/emacs.
It may also be a path to a file containing one origin per line.

There are two command forms: commands with no arguments (e.g. help, version) and that take a list of port origins (unlimited) or a single path to file containing lists of port origins, one per line. These are equivalent:

> synth just-build editors/joe editors/nano editors/libreoffice
> synth just-build /tmp/build.list   

(where the file /tmp/build.list contains:


> synth configure

Synth uses an interactive menu to configure itself. It is based on profiles that can mix and match the parts of the build system. Most people will use the "LiveSystem" profile, but advanced users may have custom bases installed elsewhere and prefer to create a profile that uses them. The configuration also covers items such as how many builders to spawn during building, whether tmpfs should be used, etc.

Synth configuration profile: LiveSystem
   [A] Ports directory            /usr/ports
   [B] Packages directory         /var/synth/live_packages
   [C] Distfiles directory        /usr/ports/distfiles
   [D] Port options directory     /var/db/ports
   [E] Build logs directory       /var/log/synth
   [F] Build base directory       /usr/obj/synth-live
   [G] System root directory      /
   [H] Compiler cache directory   disabled
   [I] Num. concurrent builders   6
   [J] Max. jobs per builder      4
   [K] Use tmpfs for work area    true
   [L] Use tmpfs for localbase    true
   [M] Display using ncurses      true
   [N] Fetch prebuilt packages    false

   [>]   Switch/create profiles
   [RET] Exit

Press key of selection:

Just press the letter of the item that needs configuring. All changes will be marked with an asterisk, and pressing the Enter key (carriage return) will save the changes.

> synth status

> synth status
> synth status [ports]
> synth status-everything

The "Status" command is unique in that there are three versions of it, and it has both the singular and ports-list form. The purpose of the "Status" command is to perform a "dry-run" of the intended command without actually changing anything on the system. It will show which packages will be deleted due to failed validity checks, and which packages will be built as a result. The "synth status" command looks at the current list of installed packages and checks the given ports tree. From that it calculates which ones are outdated, and how far the rebuild will cascade. The result is the number of packages that will be rebuilt to bring the current packages up to date. The "synth status [ports]" accepts a list of ports and checks them against the local repository, and from that determines what actually will be rebuilt. The "synth status-everything" command returns the incremental list of ports that would be built if the entire ports tree is requested (this is obviously not a command for an average user).

# synth status databases/postgresql96-server
These are the ports that would be built ([N]ew, [R]ebuild, [U]pgrade):
  N => databases/postgresql96-client
  N => devel/icu
  N => databases/postgresql96-server
Total packages that would be built: 3
The complete build list can also be found at:

> synth upgrade-system

This is a popular command. It would be used after bringing the ports tree up to date. Executing "synth upgrade-system" will perform the same analysis as "synth status", but then starting building all the required ports concurrently. When that is finished, the local repository will be updated, and finally the system's pkg(8) program will be commanded to update the system using the local repository.

synth status

During the build process, the build status is shown and updated every second. The user can see the results of recent builds (up to 50, but limited to screen size), the status of each builder, and some statistics, include system load, swap status, and the average number of packages built per hour. The "impulse" statistic is the package build rate over the last 500 seconds. The "Lines" column in the builder section is the current length of the build log, updated each second.

> synth prepare-system

This command is similar to the "synth upgrade-system" command except that it stops after rebuilding the local repository. The sysadmin can then upgrade the system using pkg(8) at their leisure.

> synth rebuild-repository

This command will do a sanity check on all built packages and remove the invalid ones. It will then (re)create a local repository comprised of the packages that remain.

> synth just-build [ports]

This command will build the list of given ports and when it has finished, the program will provide a final tally of the results and exit.

> synth build [ports]

This command will build the list of given ports, and when it has finished, it will prompt the user to answer "T" (True) or "F" (False) if they want to rebuild the local repository. Just the pre-scanning can take a few minutes so normally the answer would be "F" until the user believes the last package has been built. After the repository is rebuilt, the user will be asked another T/F question to confirm they want to install the specifically listed ports on to the system.

> synth install [ports]

This command is the same as "synth build [ports]" except it will not ask any questions. When the build is finished, it rebuilds the repository and installs the ports automatically.

> synth force [ports]

This command is similar to "synth build [ports]" but the difference is that any package that exists for the listed ports is deleted first, even if it is a perfectly valid and up-to-date package. The result of a "synth build" command could be that nothing gets built, but "synth force" will always build what it requested.

> synth test [ports]

This command is similar to "synth force [ports]", but the difference is that the ports are built under DEVELOPER mode and have additional checks. This makes the build logs suitable for submitting to FreeBSD Bugzilla (as an alternative to Poudriere)

> synth everything

The vast majority of people will not need the "synth everything" command. It builds every package in the ports tree and rebuilds the local repository (without asking) when it's done.

> synth purge-distfiles

The command will remove all previously fetched distfiles that are no longer referenced by the ports tree. It takes a few minutes to scan everything and then deletes the files en-masse without asking.


Custom make.conf

Any file that matches the path "/usr/local/etc/synth/[profile]-make.conf" where [profile] is the name of the selected configuration profile will be appended to the builders stock make.conf. Note that the default profile name is "LiveSystem", so that would make the path is "/usr/local/etc/synth/LiveSystem-make.conf" for most users.

Graceful exits

Do not hit Control-C during the build! If you want to stop building, hit the Control-Q combination. Synth will exit as soon as it can. If it's hit during the building process, it will finish the packages that are currently building but it won't start any new ones.

Port Options

Synth uses cached options if they have been saved. Synth will scan these options file before starting a build, and if any are obsolete (number of options don't match the current port, the option names are different, etc) then it will print out the problematic ports and halt, recommending that the cached options either be removed or re-saved to something valid. To build a package with non-default options, just run "make -C /usr/ports/[category]/[portname] config" before staring a build.

Build logs

Every build produces a log. By default they are located at /var/logs/synth, but this location is configurable. The log name is in the format [category]___[portname].log.

Regular users

Right now Synth can only be executed by the root user

Non-curses mode

There is a text mode for the building phase. It shows much less information than the curses-based screen, but if curses is acting up, the text mode gets the job done just fine. Also, when cron launches Synth, it is required that it be using a profile that has disabled the curses display.

Web interface

Starting with version 1.60, a dynamic web report is automatically generated for every build. The report is created in the Report subdirectory of the logs directory (/var/log/synth/Report/index.html by default).

web report

The report is updated 10 times per minute. The entire build history is retained and searchable during the run; it's reset upon subsequent runs. In addition to the standard search and navigation options, several areas of the report are clickable. Click on the Built, Failed, Ignored, and Skipped fields to click filter for results. Clicking on the Total field will remove all search filters. Additionally, every cell in the No. column will filter the history for the port origin, which is particularly useful for finding all the ports that the builders skipped due to build failures or finding the port set to IGNORE. The builder ID column cells also trigger a quick filter for all work performed by the builder.

To view the report on a localhost, simply navigate the browser to the reports directory. To view it remotely, a web server has to be installed, running and configured to expose the Synth logs directory for remote browsers.

Frequently Asked Questions

Synth fails when I run it inside a jail. What can I do?

First, there is no benefit to running Synth inside a jail. It internally creates jail-like environments for each builder and to add another layer around Synth doesn't provide any extra protection. It is recommended that you don't even bother.

Wait, you don't care about that recommendation? You demand to be able to run Synth in a jail? Okay, add the following to jail.conf:


(Courtesy of Dewayne Geraghty)

Synth can't fetch because I use a proxy server. How can I fix this?

This requires providing custom environment variables. Create a file named /usr/local/etc/synth/-environment (e.g. LiveSystem-environment) and define one variable per line, e.g.



Change the urls and port numbers to match your actual proxy server port, of course.

Synth is configured to prefetch suitable officially-built packages, but very few are actually retrieved. What's wrong?

This only happens to FreeBSD users. On FreeBSD, there are basically two official repositories: Quarterly and Latest. The 10.2 Release and later have pkg(8) configured to use the Quarterly packages by default. Earlier releases are configured to use the Latest packages.

Either repository is fine, but the provided ports tree has to match! If you decided to continue with the Quarterly branch (a fine choice if you don't like constant rebuilding) then you need to provide Synth with a SVN version of the ports tree set to the same Quarterly branch. As could be deduced from the name, a new SVN branch is created every three months, so Synth users that choose the Quarterly ports and packages need to remember to switch branches in January, April, July, and October.

If you want the newest versions of software always and still leverage prebuilt packages, then ensure pkg(8) is configured for the Latest packages and the ports tree is as well. Unlikely Quarterly users, Latest users never have to change the ports tree configuration.

Can I use Synth to show UPDATING information?

No, but you can use pkg(8) to accomplish this. Add something like this to your ~/.cshrc file:

alias pnotes    'date -v -4w +%Y%m%d | xargs pkg updating --date'

Then the next time you log in, the command "pnotes" will display the last 4 weeks worth of UPDATING entries based on what is installed on the system. Note that most entries are for portmaster and portupgrade users, and that there will be no action for Synth/pkg users for the great majority of the entries.

(Courtesy of Matt Smith)

Can redundant cached port options be removed en-masse?

Yes. It is not uncommon for an existing port options cache to contain over a 100 redundant files. This happens when people build ports on a live system and just hit "ok" when the options dialog appears. The causes the options settings to be saved, but this is unnecessary because the settings are the same as the defaults. Later this can cause issues when the port maintainer updates the options and they no longer match the saved values. The redundant files can be listed like this:

/bin/sh /usr/ports/Tools/scripts/

To delete all the redundant options, just pipe the output into rm

/bin/sh /usr/ports/Tools/scripts/ | xargs rm -rf

How does one configure Synth to use ccache?

First, install ccache:

> pkg install ccache 
> cd /usr/ports/devel/ccache && make install

Check initial configuration:

> ccache -s
cache directory                     /root/.ccache
primary config                      /root/.ccache/ccache.conf
secondary config      (readonly)    /usr/local/etc/ccache.conf
cache hit (direct)                     0
cache hit (preprocessed)               0
cache miss                             0
files in cache                         0
cache size                           0.0 kB
max cache size                       5.0 GB

Update the maximum cache size:

> ccache --max-size=15G
Set cache size limit to 15.0 GB

Set the cache location where you want it (e.g. /var/cache/ccache):

> ccache --set-config=cache_dir=/var/cache/ccache

check configuration again:

> ccache -s
cache directory                     /var/cache/ccache
primary config                      /root/.ccache/ccache.conf
secondary config      (readonly)    /usr/local/etc/ccache.conf
cache hit (direct)                     0
cache hit (preprocessed)               0
cache miss                             0
files in cache                         0
cache size                           0.0 kB
max cache size                      15.0 GB

Now run synth configure, selection option [H], and enter the value of cache directory (/var/cache/ccache in this example)

While synth is building, you can run ccache -s command repeatedly in another terminal to check if the statistics are changing during the build. If they are, ccache is properly configured.

How to configure Synth to crossbuild binaries

Synth can be configured to crossbuild packages with a bit of help from binmiscctl(1) and the qemu-user-static port. Currently, synth supports armv6 and aarch64 crossbuilds on FreeBSD. Note that synth also works natively on FreeBSD/ARM64 (aarch64), but that option is not available for FreeBSD/ARM (armv6).

The following example demonstrates how to build crossbuild armv6 from an amd64 host, and uses QemuUserModeHowTo as a reference:

First, set up a armv6 sysroot that can be used with chroot(1):

# SYSROOT=/crossbuild/armv6
# cd /usr/src
# make -j 6 TARGET=arm TARGET_ARCH=armv6 buildworld
# make DESTDIR=$SYSROOT TARGET=arm TARGET_ARCH=armv6 installworld

If this is a new sysroot, you will also need to:

# make DESTDIR=$SYSROOT TARGET=arm TARGET_ARCH=armv6 distribution

On the host environment, build qemu-user-static and copy the emulator binary into a sysroot directory that will be mounted by synth builds, eg /sbin. Register armv6 binaries to use the the emulator when chroot'd.

# synth install emulators/qemu-user-static
# cp /usr/local/bin/qemu-arm-static $SYSROOT/sbin
# binmiscctl add armelf \
  --interpreter /sbin/qemu-arm-static \
  --magic "\x7f\x45\x4c\x46\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00" \
  --mask  "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff" \
  --size 20 --set-enabled
# mount -t devfs devfs ${DESTDIR}/dev

The sysroot is now ready to be used, and can be tested:

# chroot -u root $SYSROOT
root@helios:/ # file /usr/bin/file
/usr/bin/file: ELF 32-bit LSB executable, ARM, EABI5 version 1 (FreeBSD), dynamically linked, interpreter /libexec/, for FreeBSD 11.0 (1100510), FreeBSD-style, stripped

On a new chroot environment, /var/run/ needs to be generated:

root@helios:/ # service ldconfig start

Set up separate log directories and package repos for synth on the host:

# mkdir /var/synth/armv6
# mkdir /var/log/synth-armv6

Create a new profile, eg: ArmBuild, to use when crossbuilding. In particular, change:

  • Packages directory : /var/synth/armv6
  • Build logs directory : /var/log/synth-armv6
  • System root directory : /crossbuild/armv6

To run the crossbuilding synth from the host environment, you will need to ensure that correct profile and package repository database is consulted, eg:

# env SYNTHPROFILE=ArmBuild PKG_DBDIR="${SYSROOT}/var/db/pkg" synth build x11/xorg

Current drawbacks:

  • synth upgrade-system will not work, as it updates the host, not the crossbuild

(Courtesy of Jonathan Chen)

Overview Diagrams

Relationship with ports and pkg(8)

Synth configuration summary

Significant articles on the Internet : Managing ports for multiple FreeBSD servers

Trond's place : First experiences with ports-mgmt/synth


Chris_H - FreeBSD forums member - 25 January 2016

marino@ regarding: 0.98_5 -- smooth as silk!

Just completed updating my box, using that version. Everything went flawlessly. Failures were handled gracefully, as well as all other events. Well; save the screen corruption, due to (kernel) messages being sent to it. But I didn't see anything in the Changelog, to indicate there were any changes in that regard -- wishful thinking on my part. ;)

Thank you very much, John. My dev box thanks you, also. :)

garry - FreeBSD forums member - 29 January 2016

I used synth-0.99_2 to build a new repository, reproducing what I had previously built with ports-mgmt/poudriere using the same general setup (3 jails, 3 jobs, tmpfs for the workdir and data). Synth built my 1800 packages in about 18 hours of wall time with no problems. It had taken more than 24 hours of wall time to build that repository with poudriere(8). It seems that Synth is very efficient in setting up and tearing down builders (chroot(8)s / jail(8)s). I noticed that small packages can be done in 20 seconds by Synth but take a minimum of two minutes with poudriere(8).

Synth is very pleasant to use. Thanks again.

fernandel - 2 February 2016

I am also using Synth from the first day and after all this years which I "spent" with portmaster I am so happy and thankful that is Synth in the ports and for Marinos help too. Thank you.

BTW: I start synth-upgrade system before bad time and in the morning is everything done

Crivens - Moderator FreeBSD forum - 1 Feb 2016

I for one, would take the moment to thank you for some great software!

This thread is turning into rope, sort of thing. Hopefully it will turn into some chapter of the handbook.

protocelt - Moderator FreeBSD forum - 2 Feb 2016

I have 900+ ports installed on my workstation. Last repository rebuild I did, with the ccache(1) cache fully populated, Synth took around 3.5 hours to rebuild the entire repository. I don't know how long Poudriere took on the same machine but I know it was longer. I thought there was a mistake and ports were not getting rebuilt, but after checking, they were all in fact rebuilt. It is quite fast.

PacketMan - FreeBSD forums member - 31 Jan / 3 Feb 2016

Really liking this synth. Thank you so much Marino. 🍺

Yes [Synth] a great tool; I can't wait to roll it out to all my machines.

tankist02 - FreeBSD forums member - 7 March 2016

@marino Thank a lot for the great tool and explanation what and why it does. I used to have mysterious crashes after running portmaster. These days I use synth exclusively and crashes don't happen anymore. I tried to use poudriere and it was just too much and slow-ish for my simple needs (home desktop).


Next D/Ports build tool for live systems (Alternative for Portmaster and Portupgrade tools)




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