我有这么一小段：
\documentclass{standalone}
\usepackage{tikz}
\usepackage[siunitx]{circuitikz}
\listfiles
\begin{document}
\begin{circuitikz}[
american,
opamp label/.style={xshift=-8mm, font=\small,right},
buffer label/.style={xshift=-6mm, font=\small,right}
]
\draw(0,0) node[op amp](oa1){} (oa1) node[opamp label]{OA1};
\end{circuitikz}
\end{document}
一切都运行正常，直到昨天，我将系统更新到 Ubuntu 16.04，并将其更新到 TeXLive 2015。现在它给出了错误：
! Package pgfkeys Error: I do not know the key '/tikz/opamp label' and I am going to ignore it. Perhaps you misspelled it.
See the pgfkeys package documentation for explanation.
Type H <return> for immediate help.
...
l.12 ...node[op amp](oa1){} (oa1) node[opamp label]
{OA1};
这个问题的根源是什么？
更新
问题出在american键上。如果我最后使用它或移动（比如Torbjørn 的回答）它可以工作，但是：
\documentclass{standalone}
\usepackage{tikz}
\usepackage[siunitx]{circuitikz}
\tikzset{
opamp label/.style={xshift=-8mm, font=\small,right},
buffer label/.style={xshift=-6mm, font=\small,right}
}
\begin{document}
\begin{circuitikz}[
american,
]
\draw(0,0) node[op amp](oa1){} (oa1) node[opamp label]{OA1};
\path (3.5,0) node [draw, minimum size=2cm] (lpf) {}
+(-0.8cm, -0.5cm) edge[gray, thin, ->] +(0.8cm,-0.5cm);
\end{circuitikz}
\end{document}
给出了一个令人费解的错误：
! Package tikz Error: Giving up on this path. Did you forget a semicolon?.
See the tikz package documentation for explanation.
Type H <return> for immediate help.
...
l.14 ....5cm) edge[gray, thin, ->] +(0.8cm,-0.5cm)
;
好像现在环境无法处理\path多行断线。
文件列表：
*File List*
standalone.cls 2015/07/15 v1.2 Class to compile TeX sub-files standalone
ifluatex.sty 2010/03/01 v1.3 Provides the ifluatex switch (HO)
ifpdf.sty 2011/01/30 v2.3 Provides the ifpdf switch (HO)
ifxetex.sty 2010/09/12 v0.6 Provides ifxetex conditional
xkeyval.sty 2014/12/03 v2.7a package option processing (HA)
xkeyval.tex 2014/12/03 v2.7a key=value parser (HA)
standalone.cfg 2015/07/15 v1.2 Default configuration file for 'standalone' c
lass
article.cls 2014/09/29 v1.4h Standard LaTeX document class
size10.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
tikz.sty 2015/08/07 v3.0.1a (rcs-revision 1.151)
pgf.sty 2015/08/07 v3.0.1a (rcs-revision 1.15)
pgfrcs.sty 2015/08/07 v3.0.1a (rcs-revision 1.31)
everyshi.sty 2001/05/15 v3.00 EveryShipout Package (MS)
pgfrcs.code.tex
pgfcore.sty 2010/04/11 v3.0.1a (rcs-revision 1.7)
graphicx.sty 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
graphics.sty 2016/01/03 v1.0q Standard LaTeX Graphics (DPC,SPQR)
trig.sty 2016/01/03 v1.10 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 2014/07/09 v3.0.1a (rcs-revision 1.48)
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 v3.0.1a (rcs-revision 1.7)
pgfcomp-version-1-18.sty 2007/07/23 v3.0.1a (rcs-revision 1.1)
pgffor.sty 2013/12/13 v3.0.1a (rcs-revision 1.25)
pgfkeys.sty
pgfkeys.code.tex
pgfmath.sty
pgfmath.code.tex
pgffor.code.tex
tikz.code.tex
circuitikz.sty 2015/05/15 The CircuiTikz circuit drawing package version 0.4
xstring.sty 2013/10/13 v1.7c String manipulations (C Tellechea)
siunitx.sty 2016/03/01 v2.6q A comprehensive (SI) units package
expl3.sty 2016/01/19 v6377 L3 programming layer (loader)
expl3-code.tex 2016/01/19 v6377 L3 programming layer
l3pdfmode.def 2015/11/11 v6250 L3 Experimental driver: PDF mode
xparse.sty 2016/01/19 v6377 L3 Experimental document command parser
amstext.sty 2000/06/29 v2.01 AMS text
amsgen.sty 1999/11/30 v2.0 generic functions
array.sty 2014/10/28 v2.4c Tabular extension package (FMi)
l3keys2e.sty 2016/01/19 v6377 LaTeX2e option processing using LaTeX3 keys
translator.sty 2010/06/12 ver 1.10
translator-language-mappings.tex
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
translator-basic-dictionary-English.dict
siunitx-abbreviations.cfg 2016/03/01 v2.6q siunitx: Abbreviated units
*
答案1
我不知道确切的原因，但大概是circuitikz处理添加到环境可选参数的键的方式发生了一些变化circuitikz。无论如何，一个简单的解决方案是在其他地方定义样式\tikzset，例如
\documentclass{standalone}
\usepackage{tikz}
\usepackage[siunitx]{circuitikz}
\tikzset{
opamp label/.style={xshift=-8mm, font=\small,right},
buffer label/.style={xshift=-6mm, font=\small,right}
}
\begin{document}
\begin{circuitikz}[american]
\draw(0,0) node[op amp](oa1){} (oa1) node[opamp label]{OA1};
\end{circuitikz}
\end{document}