Use a recent version of TeX Live for the Travis-CI build.

.travis.yml

@@ -1,42 +1,19 @@
 language: c
 sudo: false
 
+env:
+ - PATH="$HOME/texlive/bin/x86_64-linux:$PATH"
+
 before_install:
  - true
 
-addons:
-  apt:
-    packages:
-    - texlive-latex-base
-    - texlive-fonts-extra
-    - texlive-fonts-recommended
-    - texlive-latex-extra
-    # on 12.04: texlive-latex3, but use texlive-latex-recommended on more recent versions of Ubuntu.
-    - texlive-latex3
-    - texlive-latex-recommended
-    - pgf
-    - latex-xcolor
-    - lmodern
-    - texlive-math-extra
-
 install:
-  - echo "LaTeX extra packages:"
-  - latex_home=$(kpsewhich -var-value=TEXMFHOME)
-  - curl -L -o newunicodechar.ins http://mirrors.ctan.org/macros/latex/contrib/newunicodechar/newunicodechar.ins
-  - curl -L -o newunicodechar.dtx http://mirrors.ctan.org/macros/latex/contrib/newunicodechar/newunicodechar.dtx
-  - latex newunicodechar.ins
-  - mkdir -p "$latex_home/tex/latex/newunicodechar"
-  - mv newunicodechar.sty "$latex_home/tex/latex/newunicodechar"
-  - curl -L -o mathpartir.dtx http://mirrors.ctan.org/macros/latex/contrib/mathpartir/mathpartir.dtx
-  - curl -L -o mathpartir.ins http://mirrors.ctan.org/macros/latex/contrib/mathpartir/mathpartir.ins
-  - latex mathpartir.ins
-  - mkdir -p "$latex_home/tex/latex/mathpartir"
-  - mv mathpartir.sty "$latex_home/tex/latex/mathpartir"
-  - curl -L -o pgf.zip https://downloads.sourceforge.net/project/pgf/pgf/version%203.0.1/pgf_3.0.1.tds.zip
-  - unzip -d "$latex_home" pgf.zip
-  - curl -L -o pgfplots.zip https://downloads.sourceforge.net/project/pgfplots/pgfplots/1.15/pgfplots_1.15.tds.zip
-  - unzip -d "$latex_home" pgfplots.zip
-  - echo "Finished installing extra latex packages."
+  - echo "Installing LaTeX and LaTeX packages."
+  - curl -L -o texlive.tar.gz https://github.com/yihui/ubuntu-bin/releases/download/latest/texlive.tar.gz
+  - tar -C "$HOME/" -zxf texlive.tar.gz
+  - tlmgr update --self
+  - tlmgr install newunicodechar mathpartir pgf pgfplots bera float cancel pgfopts elocalloc environ savesym bbding wasy wasysym epigraph
+  - echo "Finished installing LaTeX and LaTeX packages."
   # ################## #
   # Actual LaTeX build #
   # ################## #

tikzlibrarytree-triangle-fit.code.tex

@@ -9,6 +9,7 @@
 % }
 % %%%%%%%
 
+\ifx\pgfmathsign\relax%
 \tikzmath{
   function sign(\x) {
     if (\x < 0) then {
@@ -22,6 +23,7 @@
     };
   };
 }
+\fi%
 
 \newif\iftrianglefitisosceles
 \newif\iftrianglefitbackground

tikzlibrarytriangle-fit.code.tex

@@ -9,6 +9,7 @@
 % }
 % %%%%%%%
 
+\ifx\pgfmathsign\relax%
 \tikzmath{
   function sign(\x) {
     if (\x < 0) then {
@@ -22,6 +23,7 @@
     };
   };
 }
+\fi%
 
 \newif\iftrianglefitisosceles
 \newif\iftrianglefitbackground