我正在运行 LuaLaTeX，如果我删除任何下面的包，或者甚至通过直接加载包来更改我的布局控制，然后我的tikzpicture编译就会按预期进行。然而，通过这种精确的设置，我得到了所示的倾斜图像。
\documentclass{exam}
%Layout control
\makeatletter
\@ifclassloaded{beamer}{}{\usepackage[letterpaper]{geometry}}
\@ifclassloaded{exam}{}{\usepackage{fancyhdr}}
\makeatother
%Packages for handling language
\usepackage[english]{babel}
\usepackage{siunitx}
%Packages for nice formatting
\usepackage{booktabs}
\usepackage{floatflt}
\usepackage{multicol}
%packages to allow creation of certain commands
\usepackage{mathtools}
\usepackage{pgffor}
%packages and options to draw figures
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\draw (0,0) to (8,0);
\end{tikzpicture}
\end{document}
我真的不知道是什么原因造成的。
*File List*
exam.cls 2015/05/07 Version 2.5 by Philip Hirschhorn
ifthen.sty 2014/09/29 v1.1c Standard LaTeX ifthen package (DPC)
article.cls 2014/09/29 v1.4h Standard LaTeX document class
size10.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
geometry.sty 2010/09/12 v5.6 Page Geometry
keyval.sty 2014/10/28 v1.15 key=value parser (DPC)
ifpdf.sty 2011/01/30 v2.3 Provides the ifpdf switch (HO)
ifvtex.sty 2010/03/01 v1.5 Detect VTeX and its facilities (HO)
ifxetex.sty 2010/09/12 v0.6 Provides ifxetex conditional
babel.sty 2014/09/25 3.9l The Babel package
english.ldf 2012/08/20 v3.3p English support from the babel system
siunitx.sty 2015/07/17 v2.6h A comprehensive (SI) units package
expl3.sty 2015/06/15 v5630 L3 programming layer (loader)
expl3-code.tex 2015/06/15 v5630 L3 programming layer
l3unicode-data.def 2015/03/01 v5544 L3 Unicode data
l3pdfmode.def 2015/05/21 v5613 L3 Experimental driver: PDF mode
xparse.sty 2015/06/15 v5630 L3 Experimental document command parser
amstext.sty 2000/06/29 v2.01
amsgen.sty 1999/11/30 v2.0
array.sty 2014/10/28 v2.4c Tabular extension package (FMi)
l3keys2e.sty 2015/06/15 v5630 LaTeX2e option processing using LaTeX3 keys
translator.sty 2010/06/12 ver 1.10
translator-language-mappings.tex
booktabs.sty 2005/04/14 v1.61803 publication quality tables
floatflt.sty 1997/07/16 v. 1.31
multicol.sty 2015/03/31 v1.8m multicolumn formatting (FMi)
mathtools.sty 2015/06/17 v1.17 mathematical typesetting tools
calc.sty 2014/10/28 v4.3 Infix arithmetic (KKT,FJ)
mhsetup.sty 2010/01/21 v1.2a programming setup (MH)
amsmath.sty 2013/01/14 v2.14 AMS math features
amsbsy.sty 1999/11/29 v1.2d
amsopn.sty 1999/12/14 v2.01 operator names
pgffor.sty 2013/12/13 v3.0.0 (rcs-revision 1.25)
pgfrcs.sty 2013/12/20 v3.0.0 (rcs-revision 1.28)
everyshi.sty 2001/05/15 v3.00 EveryShipout Package (MS)
pgfrcs.code.tex
pgfkeys.sty
pgfkeys.code.tex
pgfmath.sty
pgfmath.code.tex
pgffor.code.tex
pgfplots.sty 2015/05/02 v1.12.1 Data Visualization (1.12.1)
tikz.sty 2013/12/13 v3.0.0 (rcs-revision 1.142)
pgf.sty 2013/12/18 v3.0.0 (rcs-revision 1.14)
pgfcore.sty 2010/04/11 v3.0.0 (rcs-revision 1.7)
graphicx.sty 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
graphics.sty 2014/10/28 v1.0p Standard LaTeX Graphics (DPC,SPQR)
trig.sty 1999/03/16 v1.09 sin cos tan (DPC)
graphics.cfg 2010/04/23 v1.9 graphics configuration of TeX Live
pdftex.def 2011/05/27 v0.06d Graphics/color for pdfTeX
infwarerr.sty 2010/04/08 v1.3 Providing info/warning/error messages (HO)
ltxcmds.sty 2011/11/09 v1.22 LaTeX kernel commands for general use (HO)
pgfsys.sty 2013/11/30 v3.0.0 (rcs-revision 1.47)
pgfsys.code.tex
pgfsyssoftpath.code.tex 2013/09/09 (rcs-revision 1.9)
pgfsysprotocol.code.tex 2006/10/16 (rcs-revision 1.4)
xcolor.sty 2007/01/21 v2.11 LaTeX color extensions (UK)
color.cfg 2007/01/18 v1.5 color configuration of teTeX/TeXLive
pgfcore.code.tex
pgfcomp-version-0-65.sty 2007/07/03 v3.0.0 (rcs-revision 1.7)
pgfcomp-version-1-18.sty 2007/07/23 v3.0.0 (rcs-revision 1.1)
tikz.code.tex
luatexbase.sty 2013/05/11 v0.6 Resource management for the LuaTeX macro progr
ammer
ifluatex.sty 2010/03/01 v1.3 Provides the ifluatex switch (HO)
luatex.sty 2010/03/09 v0.4 LuaTeX basic definition package (HO)
etex.sty 2015/03/02 v2.1 eTeX basic definition package (PEB,DPC)
luatex-loader.sty 2010/03/09 v0.4 Lua module loader (HO)
luatexbase-compat.sty 2011/05/24 v0.4 Compatibility tools for LuaTeX
luatexbase-modutils.sty 2013/05/11 v0.6 Module utilities for LuaTeX
luatexbase-loader.sty 2013/05/11 v0.6 Lua module loader for LuaTeX
luatexbase-regs.sty 2011/05/24 v0.4 Registers allocation for LuaTeX
luatexbase-attr.sty 2013/05/11 v0.6 Attributes allocation for LuaTeX
luatexbase-cctb.sty 2013/05/11 v0.6 Catcodetable allocation for LuaTeX
luatexbase-mcb.sty 2013/05/11 v0.6 Callback management for LuaTeX
translator-basic-dictionary-English.dict
siunitx-abbreviations.cfg 2015/07/17 v2.6h siunitx: Abbreviated units
supp-pdf.mkii
pdftexcmds.sty 2011/11/29 v0.20 Utility functions of pdfTeX for LuaTeX (HO)
epstopdf-base.sty 2010/02/09 v2.5 Base part for package epstopdf
grfext.sty 2010/08/19 v1.1 Manage graphics extensions (HO)
kvdefinekeys.sty 2011/04/07 v1.3 Define keys (HO)
kvoptions.sty 2011/06/30 v3.11 Key value format for package options (HO)
kvsetkeys.sty 2012/04/25 v1.16 Key value parser (HO)
etexcmds.sty 2011/02/16 v1.5 Avoid name clashes with e-TeX commands (HO)
epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Live
***********
答案1
如果你注释掉该行\usepackage{pgffor}，该线就会被正确绘制。
（由于pgffor已被加载pgfplots，因此您不需要单独加载它即可使用\foreach等）。