我阅读了一些关于字体的资料：
https://wiki.contextgarden.net/ConTeXt_distribution%27s_Fonts
https://wiki.contextgarden.net/Font_Switching
https://wiki.contextgarden.net/Command/setupbodyfont
根据https://wiki.contextgarden.net/Latin_Modern我能够使用\definedfont[ec-lmtlc10]切换到 Latin Modern Light Condensed，但我无法让 Helvetica Narrow 工作，尽管它已安装在我的系统上：
❯ mtxrun --script fonts --list --all --pattern='*helvetica*'
[...]
fonts | names | accessing the data table failed
identifier familyname fontname filename subfont instances
helvetica helvetica helvetica phvr8a.afm
helveticabold helvetica helveticabold phvb8a.afm
helveticaboldoblique helvetica helveticaboldoblique phvbo8a.afm
helveticamedium helvetica helvetica phvr8a.afm
helveticanarrow helvetica helveticanarrow phvr8an.afm
helveticanarrowbold helvetica helveticanarrowbold phvb8an.afm
helveticanarrowboldoblique helvetica helveticanarrowboldoblique phvbo8an.afm
helveticanarrowoblique helvetica helveticanarrowoblique phvro8an.afm
helveticaoblique helvetica helveticaoblique phvro8a.afm
但是当我尝试通过加载它时\definedfont[name:helveticanarrow*default at 12 pt]出现以下错误：
fonts > afm loading > reading '/usr/share/texmf-dist/fonts/afm/adobe/helvetic/phvr8an.afm'
fonts > afm loading > no pfb file for '/usr/share/texmf-dist/fonts/afm/adobe/helvetic/phvr8an.afm'
fonts > afm loading > reading '/usr/share/texmf-dist/fonts/afm/adobe/helvetic/phvr8an.afm'
fonts > afm loading > no pfb file for '/usr/share/texmf-dist/fonts/afm/adobe/helvetic/phvr8an.afm'
fonts > defining > forced type 'afm' of 'phvr8an' not found
fonts > defining > font with asked name 'phvr8an' is not found using lookup 'name'
fonts > defining > unknown font 'phvr8an', loading aborted
fonts > defining > unable to define 'helveticanarrow' as 'thedefinedfont--0'
答案1
您的系统有“metrics”文件（.afm），但没有字体本身（.pfb）。您可以下载该文件NimbusSansNarrow-Bold.t1并将其重命名为phvr8an.pfb，但您应该使用默认安装的 TeX Gyre Heros Condensed，它相当于 Helvetica Narrow：
\starttext
\definedfont[name:texgyreheroscn-regular*default at 12 pt]
Hello!
\stoptext
默认安装中的完整 Heros (Helvetica) 系列：
mtxrun --script fonts --list --all --pattern='*heros*'
identifier familyname fontname filename subfont instances
texgyreherosbold texgyreheros texgyreherosbold texgyreheros-bold.otf
texgyreherosbolditalic texgyreheros texgyreherosbolditalic texgyreheros-bolditalic.otf
texgyreheroscnbold texgyreheroscn texgyreheroscondensedbold texgyreheroscn-bold.otf
texgyreheroscnbolditalic texgyreheroscn texgyreheroscondensedbolditalic texgyreheroscn-bolditalic.otf
texgyreheroscnitalic texgyreheroscn texgyreheroscondenseditalic texgyreheroscn-italic.otf
texgyreheroscnnormal texgyreheroscn texgyreheroscondenseditalic texgyreheroscn-italic.otf
texgyreheroscnregular texgyreheroscn texgyreheroscondensedregular texgyreheroscn-regular.otf
texgyreheroscondensedbold texgyreheroscn texgyreheroscondensedbold texgyreheroscn-bold.otf
texgyreheroscondensedbolditalic texgyreheroscn texgyreheroscondensedbolditalic texgyreheroscn-bolditalic.otf
texgyreheroscondenseditalic texgyreheroscn texgyreheroscondenseditalic texgyreheroscn-italic.otf
texgyreheroscondensedregular texgyreheroscn texgyreheroscondensedregular texgyreheroscn-regular.otf
texgyreherositalic texgyreheros texgyreherositalic texgyreheros-italic.otf
texgyreherosnormal texgyreheros texgyreherositalic texgyreheros-italic.otf
texgyreherosregular texgyreheros texgyreherosregular texgyreheros-regular.otf