Add webp support to GraphicsMagick

Question

A Node.js program is using gm (GraphicsMagick) to do some image manipulation/parsing. While it works locally (on my own machine), it doesn't work on the server.

Relevant output:

Error: Command failed: gm identify: No decode delegate for this image format (that-image.webp).

gm identify: Request did not return an image.

I assume this happens because webp is not supported on the server.

We tried to install libwebp-dev and then --reinstall graphicsmagick, but without any luck:

# apt-get install libwebp-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libwebp-dev is already the newest version.
# apt install --reinstall graphicsmagick
Reading package lists... Done
Building dependency tree       
Reading state information... Done
...
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 213 not upgraded.
# convert -version
Version: ImageMagick 7.0.7-9 Q16 x86_64 2017-11-24 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP 
Delegates (built-in): bzlib fontconfig freetype jbig jng jp2 jpeg lcms lzma png
tiff webp x xml zlib
gm identify -version
GraphicsMagick 1.3.20 2014-08-16 Q8 http://www.GraphicsMagick.org/
Copyright (C) 2002-2014 GraphicsMagick Group.
Additional copyrights and licenses apply to this software.
See http://www.GraphicsMagick.org/www/Copyright.html for details.
Feature Support:
  Native Thread Safe       yes
  Large Files (> 32 bit)   yes
  Large Memory (> 32 bit)  yes
  BZIP                     yes
  DPS                      no
  FlashPix                 no
  FreeType                 yes
  Ghostscript (Library)    no
  JBIG                     yes
  JPEG-2000                yes
  JPEG                     yes
  Little CMS               yes
  Loadable Modules         no
  OpenMP                   yes (201307)
  PNG                      yes
  TIFF                     yes
  TRIO                     no
  UMEM                     no
  WebP                     no
  WMF                      yes
  X11                      yes
  XML                      yes
  ZLIB                     yes
Host type: x86_64-pc-linux-gnu
Configured using the command:
  ./configure  '--build' 'x86_64-linux-gnu' '--enable-shared' '--enable-static' '--enable-libtool-verbose' '--prefix=/usr' '--mandir=${prefix}/share/man' '--infodir=${prefix}/share/info' '--docdir=${prefix}/share/doc/graphicsmagick' '--with-gs-font-dir=/usr/share/fonts/type1/gsfonts' '--with-x' '--x-includes=/usr/include/X11' '--x-libraries=/usr/lib/X11' '--without-dps' '--without-modules' '--without-frozenpaths' '--with-perl' '--with-perl-options=INSTALLDIRS=vendor' 'build_alias=x86_64-linux-gnu' 'CFLAGS=-Wall -g -fno-strict-aliasing -O2' 'LDFLAGS=' 'CXXFLAGS=-Wall -g -fno-strict-aliasing -O2'
Final Build Parameters:
  CC       = gcc -std=gnu99
  CFLAGS   = -fopenmp -Wall -g -fno-strict-aliasing -O2 -Wall -pthread
  CPPFLAGS = -I/usr/include/X11 -I/usr/include/freetype2 -I/usr/include/libxml2
  CXX      = g++
  CXXFLAGS = -Wall -g -fno-strict-aliasing -O2 -pthread
  LDFLAGS  = -L/usr/lib/X11 -L/usr/lib -L/usr/lib
  LIBS     = -ljbig -llcms2 -ltiff -lfreetype -ljasper -ljpeg -lpng12 -lwmflite -lXext -lSM -lICE -lX11 -llzma -lbz2 -lxml2 -lz -lm -lgomp -lpthread

My local machine outputs:

$ convert --version
Version: ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC Modules OpenMP 
Delegates (built-in): bzlib djvu fftw fontconfig freetype jbig jng jpeg lcms lqr ltdl lzma openexr pangocairo png tiff wmf x xml zlib
$ gm identify -version 
GraphicsMagick 1.3.26 2017-07-04 Q16 http://www.GraphicsMagick.org/
Copyright (C) 2002-2017 GraphicsMagick Group.
Additional copyrights and licenses apply to this software.
See http://www.GraphicsMagick.org/www/Copyright.html for details.
Feature Support:
  Native Thread Safe       yes
  Large Files (> 32 bit)   yes
  Large Memory (> 32 bit)  yes
  BZIP                     yes
  DPS                      no
  FlashPix                 no
  FreeType                 yes
  Ghostscript (Library)    no
  JBIG                     yes
  JPEG-2000                no
  JPEG                     yes
  Little CMS               yes
  Loadable Modules         no
  OpenMP                   yes (201511)
  PNG                      yes
  TIFF                     yes
  TRIO                     no
  UMEM                     no
  WebP                     yes
  WMF                      yes
  X11                      yes
  XML                      yes
  ZLIB                     yes
Host type: x86_64-pc-linux-gnu
Configured using the command:
  ./configure  '--build' 'x86_64-linux-gnu' '--enable-shared' '--enable-static' '--enable-libtool-verbose' '--prefix=/usr' '--mandir=${prefix}/share/man' '--infodir=${prefix}/share/info' '--docdir=${prefix}/share/doc/graphicsmagick' '--with-gs-font-dir=/usr/share/fonts/type1/gsfonts' '--with-x' '--x-includes=/usr/include/X11' '--x-libraries=/usr/lib/X11' '--without-dps' '--without-modules' '--without-frozenpaths' '--with-webp' '--with-perl' '--with-perl-options=INSTALLDIRS=vendor' '--enable-quantum-library-names' '--with-quantum-depth=16' 'build_alias=x86_64-linux-gnu' 'CFLAGS=-Wall -g -fno-strict-aliasing -O2' 'LDFLAGS=' 'CXXFLAGS=-Wall -g -fno-strict-aliasing -O2'
Final Build Parameters:
  CC       = gcc
  CFLAGS   = -fopenmp -Wall -g -fno-strict-aliasing -O2 -Wall -pthread
  CPPFLAGS = -I/usr/include/X11 -I/usr/include/freetype2 -I/usr/include/libxml2
  CXX      = g++
  CXXFLAGS = -Wall -g -fno-strict-aliasing -O2 -pthread
  LDFLAGS  = -L/usr/lib/X11
  LIBS     = -ljbig -lwebp -llcms2 -ltiff -lfreetype -ljpeg -lpng16 -lwmflite -lXext -lSM -lICE -lX11 -llzma -lbz2 -lxml2 -lz -lm -lgomp -lpthread

The first thing I see is that the server has ImageMagick installed as well. However, it seems that gm identify fails, not convert.

I'm not sure how to solve this. How can we add webp support to GraphicsMagick? Should we get rid of ImageMagick?