在 Azure 上使用 Bitnami WordPress 堆栈的 Ubuntu 18.04.4 LTS 上，我尝试让 Imagemagick 和 Ghostscript 运行，以便 WordPress 创建 PDF 缩略图。一个简单的转换测试给出了错误。当我搜索错误消息时，它们让我越来越深入地陷入各种兔子洞，包括缺少库、手动添加符号链接、从源代码编译等。运行一个流行的图像转换程序似乎不应该那么难。我错过了什么？
以下是版本和失败的测试：
/tmp$ sudo apt update
All packages are up to date.
/tmp$ sudo apt install imagemagick
imagemagick is already the newest version (8:6.9.7.4+dfsg-16ubuntu6.8).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
/tmp$ sudo apt install ghostscript
ghostscript is already the newest version (9.26~dfsg+0-0ubuntu0.18.04.12).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
/tmp$ which convert
/opt/bitnami/common/bin/convert
/tmp$ convert -version
Version: ImageMagick 6.9.8-3 Q16 x86_64 2019-04-03 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC Modules
Delegates (built-in): bzlib freetype jng jpeg ltdl png tiff wmf xml zlib
/tmp$ which ghostscript
/usr/bin/ghostscript
/tmp$ gs -version
GPL Ghostscript 9.26 (2018-11-20)
Copyright (C) 2018 Artifex Software, Inc. All rights reserved.
/tmp$ convert -verbose resume.pdf resume.jpg
'gs' -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 '-sDEVICE=pngalpha' -dTextAlphaBits=4 -dGraphicsAlphaBits=4 '-r72x72' '-sOutputFile=/tmp/magick-38144ceME6-csnc4X%d' '-f/tmp/magick-38144tpfIz6n76qfI' '-f/tmp/magick-38144AH22zQfdNQqs'
gs: /opt/bitnami/common/lib/libtiff.so.5: no version information available (required by /usr/lib/x86_64-linux-gnu/libgs.so.9)
gs: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgs.so.9: undefined symbol: FT_Property_Set
.convert.bin: no images defined `resume.jpg' @ error/convert.c/ConvertImageCommand/3258.
编辑根据评论的要求：
~$ echo $LD_LIBARY_PATH
~$ ldd $(which conver)
ldd: missing file arguments
Try `ldd --help' for more information.
~$ ldd $(which convert)
not a dynamic executable
~$ ldd /usr/bin/ghostscript
linux-vdso.so.1 (0x00007fffc5be3000)
libgs.so.9 => /usr/lib/x86_64-linux-gnu/libgs.so.9 (0x00007f3614e95000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f3614aa4000)
libtiff.so.5 => /usr/lib/x86_64-linux-gnu/libtiff.so.5 (0x00007f361482d000)
libcupsimage.so.2 => /usr/lib/x86_64-linux-gnu/libcupsimage.so.2 (0x00007f3614624000)
libcups.so.2 => /usr/lib/x86_64-linux-gnu/libcups.so.2 (0x00007f3614398000)
libijs-0.35.so => /usr/lib/x86_64-linux-gnu/libijs-0.35.so (0x00007f3614192000)
libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f3613f60000)
libjbig2dec.so.0 => /usr/lib/x86_64-linux-gnu/libjbig2dec.so.0 (0x00007f3613d48000)
libjpeg.so.8 => /usr/lib/x86_64-linux-gnu/libjpeg.so.8 (0x00007f3613ae0000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f36138c3000)
liblcms2.so.2 => /usr/lib/x86_64-linux-gnu/liblcms2.so.2 (0x00007f361366b000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f36132cd000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f36130c9000)
libidn.so.11 => /lib/x86_64-linux-gnu/libidn.so.11 (0x00007f3612e96000)
libpaper.so.1 => /usr/lib/x86_64-linux-gnu/libpaper.so.1 (0x00007f3612c92000)
libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f3612a4d000)
libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f3612799000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f361257a000)
/lib64/ld-linux-x86-64.so.2 (0x00007f3616241000)
liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f3612354000)
libjbig.so.0 => /usr/lib/x86_64-linux-gnu/libjbig.so.0 (0x00007f3612146000)
libgssapi_krb5.so.2 => /usr/lib/x86_64-linux-gnu/libgssapi_krb5.so.2 (0x00007f3611efb000)
libgnutls.so.30 => /usr/lib/x86_64-linux-gnu/libgnutls.so.30 (0x00007f3611b95000)
libavahi-common.so.3 => /usr/lib/x86_64-linux-gnu/libavahi-common.so.3 (0x00007f3611989000)
libavahi-client.so.3 => /usr/lib/x86_64-linux-gnu/libavahi-client.so.3 (0x00007f3611778000)
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f3611546000)
libkrb5.so.3 => /usr/lib/x86_64-linux-gnu/libkrb5.so.3 (0x00007f3611270000)
libk5crypto.so.3 => /usr/lib/x86_64-linux-gnu/libk5crypto.so.3 (0x00007f361103e000)
libcom_err.so.2 => /lib/x86_64-linux-gnu/libcom_err.so.2 (0x00007f3610e3a000)
libkrb5support.so.0 => /usr/lib/x86_64-linux-gnu/libkrb5support.so.0 (0x00007f3610c2f000)
libp11-kit.so.0 => /usr/lib/x86_64-linux-gnu/libp11-kit.so.0 (0x00007f3610900000)
libidn2.so.0 => /usr/lib/x86_64-linux-gnu/libidn2.so.0 (0x00007f36106e3000)
libunistring.so.2 => /usr/lib/x86_64-linux-gnu/libunistring.so.2 (0x00007f3610365000)
libtasn1.so.6 => /usr/lib/x86_64-linux-gnu/libtasn1.so.6 (0x00007f3610152000)
libnettle.so.6 => /usr/lib/x86_64-linux-gnu/libnettle.so.6 (0x00007f360ff1c000)
libhogweed.so.4 => /usr/lib/x86_64-linux-gnu/libhogweed.so.4 (0x00007f360fce8000)
libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f360fa67000)
libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f360f81a000)
libkeyutils.so.1 => /lib/x86_64-linux-gnu/libkeyutils.so.1 (0x00007f360f616000)
libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f360f3fb000)
libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f360f1f3000)
libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f360ef6f000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f360ed67000)
liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f360eb4b000)
libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f360e82f000)
libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f360e61a000)
答案1
在 Bitnami 论坛上发布此问题后，我收到了建议卸载 Ghostscript 9.26 并将 9.27 二进制文件直接从 Github 上传到服务器路径。令我惊讶的是，这立即允许 Imagemagick 工作。WordPress 中的 PDF 缩略图生成也可以正常工作。
基于这个帖子，下面是我用来卸载 Ghostscript 并从 Github 获取 9.27 二进制文件的命令：
$ sudo apt remove ghostscript
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
fonts-droid-fallback fonts-noto-mono libcupsfilters1 libcupsimage2 libgs9 libgs9-common
libijs-0.35 libjbig2dec0 libpaper-utils libpaper1 poppler-data
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
ghostscript
0 upgraded, 0 newly installed, 1 to remove and 3 not upgraded.
After this operation, 229 kB disk space will be freed.
Do you want to continue? [Y/n] y
(Reading database ... 128918 files and directories currently installed.)
Removing ghostscript (9.26~dfsg+0-0ubuntu0.18.04.12) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
~$ $ cd /tmp && curl -LO https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs927/ghostscript-9.27-linux-x86_64.tgz
$: command not found
~$ cd /tmp && curl -LO https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs927/ghostscript-9.27-linux-x86_64.tgz
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 644 100 644 0 0 2730 0 --:--:-- --:--:-- --:--:-- 2775
100 11.5M 100 11.5M 0 0 7733k 0 0:00:01 0:00:01 --:--:-- 21.9M
/tmp$ tar -xzf ghostscript-9.27-linux-x86_64.tgz
/tmp$ sudo mv ghostscript-9.27-linux-x86_64/gs-927-linux-x86_64 /usr/local/bin/gs
/tmp$ rm -r ghostscript-9.27-linux-x86_64 ghostscript-9.27-linux-x86_64.tgz
/tmp$ gs -version
GPL Ghostscript 9.27 (2019-04-04)
Copyright (C) 2018 Artifex Software, Inc. All rights reserved.
/tmp$ convert -verbose resume.pdf resume.jpg
'gs' -q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 '-sDEVICE=pngalpha' -dTextAlphaBits=4 -dGraphicsAlphaBits=4 '-r72x72' '-sOutputFile=/tmp/magick-27002C4cvCbSgCyYC%d' '-f/tmp/magick-27002GcI2PwMTOpvp' '-f/tmp/magick-2700234-pb9vPGw2b'
/tmp/magick-27002C4cvCbSgCyYC1 PNG 594x774 594x774+0+0 8-bit sRGB 28.3KB 0.030u 0:00.039
/tmp/magick-27002C4cvCbSgCyYC2 PNG 594x774 594x774+0+0 8-bit sRGB 25.3KB 0.040u 0:00.030
resume.pdf[0] PDF 594x774 594x774+0+0 16-bit sRGB 28.3KB 0.040u 0:00.030
resume.pdf[1] PDF 594x774 594x774+0+0 16-bit sRGB 28.3KB 0.000u 0:00.000
resume.pdf=>resume-0.jpg[0] PDF 594x774 594x774+0+0 16-bit Bilevel Gray 133KB 0.030u 0:00.050
resume.pdf=>resume-1.jpg[1] PDF 594x774 594x774+0+0 16-bit Bilevel Gray 122KB 0.060u 0:00.079