Files
klammertext/doc/install/linux_source_install.md
Andy Kopra 61987c8b1f Render correctly under a sandboxed browser; unbulleted contents
mdpdf drives a headless Chromium, and a browser installed as a flatpak --
which is what the Pop!_Shop installs, and so the ordinary case on a Pop!_OS
or System76 machine -- was unusable in two ways, the second of them silent.

It was not found at all.  A flatpak puts nothing on PATH and nothing in
/opt, and its wrapper is named com.brave.Browser rather than brave-browser,
so adding the export directory to PATH would not have helped either.  The
application ids are now looked for in the flatpak export directories, after
every native browser, so a native one still wins where there is one.

Found, it then rendered in the wrong fonts and reported success.  The
@font-face URLs pointed into the font store, which the sandbox cannot read,
and a browser does not report a font it cannot fetch -- it substitutes.  The
PDF came out in a default serif and nothing said so.  Granting the path
would not have travelled either: sandbox filesystem permissions differ from
one application to the next, so a scheme resting on a path works with one
browser and fails with another on the same machine.

So the document, its fonts and its images are now served to the browser
over the loopback interface instead of being passed as file:// paths.  Every
sandbox shares the network namespace -- the DevTools connection already
depends on it -- so this needs no filesystem permission from any sandbox,
present or future.  A --keep-html copy is still written with file:// URLs,
so it works when nothing is serving it.

A font that fails to load is now an error rather than a substitution: the
page is asked whether each requested family arrived, and no PDF is written
if one did not.  A finished-looking document in the wrong typeface is the
worst failure this program can have.

Separately, a table-of-contents entry no longer carries a bullet.  An entry
is a section title, and a marker in front of it reads as a list of things
rather than as a contents; ordinary bulleted lists are unaffected.

 (from dev 12929fdff53b)
2026-08-09 20:24:20 +02:00

10 KiB

Klammertext source installation on Linux (Ubuntu / Pop!_OS)

This document describes how to build and install Klammertext from source on a Linux system — Ubuntu or Pop!_OS; the steps are identical — without using the container. A source installation gives full access to all @eval modes, including :haskell and :shell commands that depend on locally installed software.

For the container installation on Linux, see linux_container_install.md.

Prerequisites

The following packages are required to build Klammertext:

sudo apt-get update
sudo apt-get install g++ make python3-dev

The C++ compiler must support C++20. GCC 11 or later is required (Ubuntu 22.04 and later include GCC 12+).

The SKS @image klammer requires OpenImageIO Python bindings. These must match the Python version that ktext is built against (check with python3.XX -c "import OpenImageIO"). For example, if ktext links against Python 3.12:

pip3.12 install OpenImageIO

Verify:

g++ --version

Clone the repository

git clone https://git.andykopra.com/ack/klammertext.git
cd klammertext

Environment variables

Klammertext's runtime environment is provided by a single self-configuring file. Source it from your shell profile (e.g., ~/.bashrc or ~/.zshrc):

source /path/to/klammertext/env/runtime.env

It self-locates KLAMMERTEXT_HOME from its own path, adds bin/ and tst/ to PATH (plus the newest ~/external/texlive/<year>/bin/<arch> if a TeX Live is installed there), sets LD_LIBRARY_PATH so libklammertext.so is found, and sets the LSan suppressions. There is no per-host or per-OS variable to set. For a TeX Live or library in a non-standard location, add it to an optional, gitignored env/runtime.env.local (sourced at the end).

After editing your shell profile, reload it:

source ~/.bashrc

Configure the build

No build configuration is needed. The single env/makefile.env is cross-platform: it reads KLAMMERTEXT_HOME from the environment (set by runtime.env above), auto-detects the platform with uname, and auto-detects Python with python3-config — no hardcoded version and no per-host file to edit. Verify the Python development headers are present:

python3-config --includes    # prints -I.../python3.XX for your Python

If python3-config is missing, install your distribution's python3-dev (Debian/Ubuntu) or python3-devel (Fedora/RHEL) package.

Build

Build the shared library, the SKS components, and the three commands with a single command: make -C com builds its prerequisites in mac/ and sks/ first, then the commands. The build is optimized (-O3) by default — the build you want to install and run:

make -C com -j        # lib/libklammertext.so + sks/*.so + bin/{ktext,kdesc,kdiag}

(For a slower -O0 debug build with AddressSanitizer, intended for development, prefix DEBUG=1: DEBUG=1 make -C com -j.)

Verify the build:

ktext -s '@eval 1 + 1 @' -d

This should print 2. For a quick document smoke test, create a small file and render it to HTML:

cat > hello.kt <<'EOF'
@document
:structure article
:title Hello
:text
@s1 Hello, Klammertext @

This document was built from source.
@
EOF
ktext hello.kt -t html          # writes hello/index.html

TeX Live (for PDF output)

The Standard Klammer Set uses XeLaTeX for the pdf target. Build a complete Klammertext TeX Live tree with the bundled script, giving it a destination directory under ~/external/texlive/<year> — the location runtime.env auto-detects. The script needs perl, xz-utils, fontconfig, and either wget or curl:

sudo apt-get install perl wget xz-utils fontconfig
bash $KLAMMERTEXT_HOME/doc/install/texlive_additional_packages.sh ~/external/texlive/2026

This installs scheme-small plus the additional packages the SKS needs and rebuilds all formats, fetching the binaries for your architecture. It writes a KLAMMERTEXT_BUILD_INFO.txt provenance file (mirror, release, package list, date) into the tree.

Because the tree lives under ~/external/texlive/2026, runtime.env finds it automatically — open a new shell (or re-source runtime.env) and xelatex will be on PATH. No manual KLAMMERTEXT_TEXLIVE_BIN is needed.

If you would rather reuse a TeX Live you already have, point runtime.env at it from the gitignored escape hatch instead, and install the SKS's extra packages into it yourself (the package list is in doc/install/texlive_additional_packages.sh):

cat >> "$KLAMMERTEXT_HOME/env/runtime.env.local" <<'EOF'
export KLAMMERTEXT_TEXLIVE_BIN=/path/to/texlive/bin/x86_64-linux
export PATH="$KLAMMERTEXT_TEXLIVE_BIN:$PATH"
EOF

Verify and test (reusing the hello.kt from the Build section):

xelatex --version
ktext hello.kt -t pdf           # writes hello.pdf

Optional: Haskell (for @eval :haskell)

The @eval :haskell mode requires runghc, which is part of the Haskell toolchain. Alternatively, the akopra/klammertext:haskell container image includes GHC (see linux_container_install.md).

The recommended way to install Haskell on Ubuntu is via ghcup:

curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh

Follow the prompts to install GHC, cabal, and related tools. After installation, ensure the ghcup bin directory is in your PATH:

export PATH=$HOME/.ghcup/bin:$PATH

Verify:

runghc --version

Test in Klammertext:

ktext -s '@eval :haskell main = putStr "Hello from Haskell" @' -d

Optional: the mdpdf command (Markdown to PDF)

Klammertext ships a second, independent route in sks/tns/: mdpdf renders a Markdown file to PDF through a headless browser, bypassing Klammertext entirely. It is for a document that is not written in Klammertext — one you have not converted yet, or one whose Markdown is not worth converting.

The command is a shell function that env/runtime.env defines, so if you source that file (see Environment variables above) you already have it — in shells started after the installation. In a shell that was already running, source it again:

source $KLAMMERTEXT_HOME/env/runtime.env
type mdpdf                      # mdpdf is a shell function

Two things it needs that the distribution does not install:

# 1. The Markdown renderer, in a virtual environment of its own.  PEP 668
#    forbids installing it into the system Python, so this is not optional
#    and not a system package.
python3 $KLAMMERTEXT_HOME/sks/tns/md_to_pdf.py --setup

# 2. A Chromium-based browser -- Brave, Chrome or Chromium -- which is the
#    renderer.  Any one of them will do; install whichever you prefer.
sudo apt install chromium-browser

A browser installed as a flatpak works too and is found without being told: that is what the Pop!_Shop installs on Pop!_OS, and a flatpak puts nothing on PATH, so the command looks for the application by name in the flatpak export directories as well. The document is served to the browser over the loopback interface rather than handed to it as a file path, so a sandboxed browser needs no filesystem permission of any kind — including none to reach the fonts, which is what silently cost a flatpak render its typography before this was so.

Then:

mdpdf notes.md                  # writes notes.pdf beside it
mdpdf notes                     # the .md may be left off

It supplies the fonts, the size matching and the code wrapping, and completes on *.md at the TAB key. Each default is a variable you may set in your shell profile — MDPDF_SERIF, MDPDF_SANS, MDPDF_MONO, MDPDF_MATCH, MDPDF_WRAP, and MDPDF_BROWSER for a browser installed somewhere the command does not look. Any option of the underlying md_to_pdf.py may also be given on the command line, where it overrides the default:

mdpdf notes.md --paper letter --margin 0.75

The stylesheet it applies is sks/tns/markdown.css; copy it, edit the copy, and pass --css yourcopy.css to render to your own taste.

Directory layout after build

klammertext/
├── bin/          ktext, kdesc, kdiag executables (after build)
├── lib/          libklammertext.so shared library (after build)
├── mac/          Klammermachine C++ source
├── sks/          Standard Klammer Set (.k files and .so modules)
│   ├── document/ document.so
│   ├── kutil/    kutil.o
│   └── target/   html_util.o, latex_util.o
├── com/          command source (ktext, kdesc, kdiag) and Makefile
├── doc/          installation guides (doc/install) and editor support (doc/edit)
└── tst/          test suites

Verifying the installation

Run the following commands to verify that everything works:

# Basic evaluation (Python)
ktext -s '@eval 1 + 1 @' -d

# Shell evaluation
ktext -s '@eval :shell date @' -d

# Show machine state (SKS is loaded by default)
ktext -s '' -m

# HTML and PDF output (uses the hello.kt from the Build section)
ktext hello.kt -t html
ktext hello.kt -t pdf     # requires TeX Live

# Haskell evaluation (requires ghcup)
ktext -s '@eval :haskell main = putStr "42" @' -d

# Run unit tests
make -C $KLAMMERTEXT_HOME/tst test

Updating

To update an existing source installation to the latest version:

cd $KLAMMERTEXT_HOME
git pull
make -C com -j             # rebuild library, SKS components, and commands (optimized)

The TeX Live tree only needs rebuilding if the SKS's package requirements changed (rare); when they do, re-run the script from the TeX Live section above.

Troubleshooting

"libklammertext.so: cannot open shared object file" Ensure LD_LIBRARY_PATH includes $KLAMMERTEXT_HOME/lib:

export LD_LIBRARY_PATH=$KLAMMERTEXT_HOME/lib:$LD_LIBRARY_PATH

"KLAMMERTEXT_HOME is not set" Set the environment variable as described in the Environment variables section above.

"python3.XX/Python.h: No such file or directory" Install the Python development headers:

sudo apt-get install python3-dev

"xelatex: command not found" (when using -t pdf) Install TeX Live and ensure its bin directory is in PATH.

"@eval :haskell requires runghc" Install Haskell via ghcup as described in the Optional: Haskell section.