Package: diffoscope Version: 78 Severity: normal Dear Maintainer,
diff(1) first reads the contents of one file then the next one: https://sources.debian.net/src/diffutils/1:3.5-3/src/io.c/#L552 This means that if the "files" are actually FIFOs connected to the output of a process, as they are in many cases in diffoscope, the second process has to wait for diff(1) to fully read the output of the first process, before it itself can run. This prevents both processes from running in parallel. An appropriate fix would be to store the output of at least one of the commands into a temporary file, and have diff(1) read from this instead. This has to be done carefully however, to make sure that diff(1) doesn't accidentally read it before the process is finished. X -- System Information: Debian Release: 9.0 APT prefers testing APT policy: (990, 'testing'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'buildd-unstable'), (300, 'unstable'), (100, 'experimental'), (1, 'experimental-debug') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.9.0-3-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages diffoscope depends on: ii python3-libarchive-c 2.1-3.1 ii python3-magic 1:5.30-1 ii python3-pkg-resources 33.1.1-1 pn python3:any <none> Versions of packages diffoscope recommends: ii acl 2.2.52-3+b1 ii apktool 2.2.1+dfsg-2 ii binutils-multiarch 2.28-5 ii bzip2 1.0.6-8.1 ii caca-utils 0.99.beta19-2+b2 ii colord 1.3.3-2 ii default-jdk [java-sdk] 2:1.8-58 ii default-jdk-headless 2:1.8-58 ii enjarify 1:1.0.3-3 ii fontforge-extras 0.3-4 pn fp-utils <none> ii genisoimage 9:1.1.11-3+b2 ii gettext 0.19.8.1-2 ii ghc 8.0.1-17+b1 ii ghostscript 9.20~dfsg-3.2 ii gnupg 2.1.18-6 ii imagemagick 8:6.9.7.4+dfsg-8 ii imagemagick-6.q16 [imagemagick] 8:6.9.7.4+dfsg-8 ii jsbeautifier 1.6.4-6 ii llvm 1:3.8-36 ii mono-utils 4.6.2.7+dfsg-1 ii openjdk-8-jdk [java-sdk] 8u131-b11-2 ii openssh-client 1:7.4p1-10 ii pdftk 2.02-4+b2 ii poppler-utils 0.48.0-2 ii python3-argcomplete 1.8.1-1 ii python3-debian 0.1.30 pn python3-guestfs <none> ii python3-progressbar 2.3-4 ii python3-rpm 4.12.0.2+dfsg1-2 ii python3-tlsh 3.4.4+20151206-1+b2 ii rpm2cpio 4.12.0.2+dfsg1-2 ii sng 1.1.0-1+b1 ii sqlite3 3.16.2-3 ii squashfs-tools 1:4.3-3+b1 ii unzip 6.0-21 ii vim-common 2:8.0.0197-4 ii xxd 2:8.0.0197-4 ii xz-utils 5.2.2-1.2+b1 Versions of packages diffoscope suggests: ii libjs-jquery 3.1.1-2 -- no debconf information