diff --git a/pkgs/applications/science/math/giac/default.nix b/pkgs/applications/science/math/giac/default.nix
index 8c391e25322..f89fe3e1db3 100644
--- a/pkgs/applications/science/math/giac/default.nix
+++ b/pkgs/applications/science/math/giac/default.nix
@@ -1,10 +1,9 @@
 { stdenv, lib, fetchurl, fetchpatch, texlive, bison, flex, lapack, blas
 , gmp, mpfr, pari, ntl, gsl, mpfi, ecm, glpk, nauty
 , readline, gettext, libpng, libao, gfortran, perl
-, enableGUI ? false, libGL ? null, libGLU ? null, xorg ? null, fltk ? null
+, enableGUI ? false, libGL, libGLU, xorg, fltk
 }:
 
-assert enableGUI -> libGLU != null && libGL != null && xorg != null && fltk != null;
 assert (!blas.isILP64) && (!lapack.isILP64);
 
 stdenv.mkDerivation rec {
diff --git a/pkgs/applications/science/math/palp/default.nix b/pkgs/applications/science/math/palp/default.nix
index 97b5f88e55b..2866b4b9469 100644
--- a/pkgs/applications/science/math/palp/default.nix
+++ b/pkgs/applications/science/math/palp/default.nix
@@ -1,4 +1,5 @@
-{ lib, stdenv
+{ lib
+, stdenv
 , fetchurl
 , dimensions ? 6 # works for <= dimensions dimensions, but is only optimized for that exact value
 , doSymlink ? true # symlink the executables to the default location (without dimension postfix)
@@ -25,8 +26,8 @@ stdenv.mkDerivation rec {
   '';
 
   preBuild = ''
-      echo Building PALP optimized for ${dim} dimensions
-      sed -i "s/^#define[^a-zA-Z]*POLY_Dmax.*/#define POLY_Dmax ${dim}/" Global.h
+    echo Building PALP optimized for ${dim} dimensions
+    sed -i "s/^#define[^a-zA-Z]*POLY_Dmax.*/#define POLY_Dmax ${dim}/" Global.h
   '';
 
   # palp has no tests of its own. This test is an adapted sage test that failed
@@ -42,14 +43,14 @@ stdenv.mkDerivation rec {
   '';
 
   installPhase = ''
-    mkdir -p "$out/bin"
+    mkdir -p $out/bin
     for file in poly class cws nef mori; do
-        cp -p $file.x "$out/bin/$file-${dim}d.x"
+      cp -p $file.x "$out/bin/$file-${dim}d.x"
     done
   '' + lib.optionalString doSymlink ''
-    cd "$out/bin"
+    cd $out/bin
     for file in poly class cws nef mori; do
-        ln -sf $file-6d.x $file.x
+      ln -sf $file-6d.x $file.x
     done
   '';
 
diff --git a/pkgs/development/compilers/zz/default.nix b/pkgs/development/compilers/zz/default.nix
index 7dfa462e225..81c6e546e95 100644
--- a/pkgs/development/compilers/zz/default.nix
+++ b/pkgs/development/compilers/zz/default.nix
@@ -31,7 +31,7 @@ rustPlatform.buildRustPackage rec {
   '';
 
   meta = with lib; {
-    description = "🍺🐙 ZetZ a zymbolic verifier and tranzpiler to bare metal C";
+    description = "ZetZ a zymbolic verifier and tranzpiler to bare metal C";
     homepage = "https://github.com/zetzit/zz";
     license = licenses.mit;
     maintainers = [ maintainers.marsam ];
diff --git a/pkgs/development/libraries/arb/default.nix b/pkgs/development/libraries/arb/default.nix
index 1c356b59d8a..527545e683f 100644
--- a/pkgs/development/libraries/arb/default.nix
+++ b/pkgs/development/libraries/arb/default.nix
@@ -1,26 +1,32 @@
-{lib, stdenv, fetchFromGitHub, mpir, gmp, mpfr, flint}:
+{ lib, stdenv, fetchFromGitHub, mpir, gmp, mpfr, flint }:
+
 stdenv.mkDerivation rec {
   pname = "arb";
   version = "2.17.0";
+
   src = fetchFromGitHub {
     owner = "fredrik-johansson";
     repo = pname;
     rev = version;
     sha256 = "05lpy3hkl5f8ik19aw40cqydrb932xaf2n8hbq9ib5dnk7f010p1";
   };
-  buildInputs = [mpir gmp mpfr flint];
+
+  buildInputs = [ mpir gmp mpfr flint ];
+
   configureFlags = [
     "--with-gmp=${gmp}"
     "--with-mpir=${mpir}"
     "--with-mpfr=${mpfr}"
     "--with-flint=${flint}"
   ];
+
   doCheck = true;
+
   meta = with lib; {
     description = "A library for arbitrary-precision interval arithmetic";
     homepage = "https://arblib.org/";
-    license = lib.licenses.lgpl21Plus;
+    license = licenses.lgpl21Plus;
     maintainers = teams.sage.members;
-    platforms = lib.platforms.unix;
+    platforms = platforms.unix;
   };
 }
diff --git a/pkgs/development/python-modules/agate-sql/default.nix b/pkgs/development/python-modules/agate-sql/default.nix
index 29bbfa81ed2..fb080bcc11b 100644
--- a/pkgs/development/python-modules/agate-sql/default.nix
+++ b/pkgs/development/python-modules/agate-sql/default.nix
@@ -1,20 +1,24 @@
 { lib, fetchPypi, buildPythonPackage, agate, sqlalchemy, crate }:
 
 buildPythonPackage rec {
-    pname = "agate-sql";
-    version = "0.5.5";
+  pname = "agate-sql";
+  version = "0.5.5";
 
-    src = fetchPypi {
-      inherit pname version;
-      sha256 = "50a39754babef6cd0d1b1e75763324a49593394fe46ab1ea9546791b5e6b69a7";
-    };
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "50a39754babef6cd0d1b1e75763324a49593394fe46ab1ea9546791b5e6b69a7";
+  };
 
-    propagatedBuildInputs = [ agate sqlalchemy crate ];
+  propagatedBuildInputs = [ agate sqlalchemy crate ];
 
-    meta = with lib; {
-      description = "Adds SQL read/write support to agate.";
-      homepage    = "https://github.com/wireservice/agate-sql";
-      license     = with licenses; [ mit ];
-      maintainers = with maintainers; [ vrthra ];
-    };
+  pythonImportsCheck = [ "agatesql" ];
+
+  meta = with lib; {
+    description = "Adds SQL read/write support to agate.";
+    homepage = "https://github.com/wireservice/agate-sql";
+    license = with licenses; [ mit ];
+    maintainers = with maintainers; [ vrthra ];
+    # FAIL: test_to_sql_create_statement_with_schema (tests.test_agatesql.TestSQL)
+    broken = true;
+  };
 }
diff --git a/pkgs/development/python-modules/dopy/default.nix b/pkgs/development/python-modules/dopy/default.nix
index 538a861c9f4..9bd32d1ba4a 100644
--- a/pkgs/development/python-modules/dopy/default.nix
+++ b/pkgs/development/python-modules/dopy/default.nix
@@ -5,18 +5,22 @@
 }:
 
 buildPythonPackage {
-  version = "2016-01-04";
   pname = "dopy";
+  version = "2016-01-04";
 
   src = pkgs.fetchFromGitHub {
     owner = "Wiredcraft";
     repo = "dopy";
     rev = "cb443214166a4e91b17c925f40009ac883336dc3";
-    sha256 ="0ams289qcgna96aak96jbz6wybs6qb95h2gn8lb4lmx2p5sq4q56";
+    sha256 = "0ams289qcgna96aak96jbz6wybs6qb95h2gn8lb4lmx2p5sq4q56";
   };
 
   propagatedBuildInputs = [ requests six ];
 
+  # contains no tests
+  doCheck = false;
+  pythonImportsCheck = [ "dopy" ];
+
   meta = with pkgs.lib; {
     description = "Digital Ocean API python wrapper";
     homepage = "https://github.com/Wiredcraft/dopy";
diff --git a/pkgs/servers/xmpp/biboumi/default.nix b/pkgs/servers/xmpp/biboumi/default.nix
index 74d8d9ae520..50d2cfa964e 100644
--- a/pkgs/servers/xmpp/biboumi/default.nix
+++ b/pkgs/servers/xmpp/biboumi/default.nix
@@ -1,6 +1,13 @@
-{ lib, stdenv, fetchurl, fetchgit, cmake, libuuid, expat, sqlite, libidn,
-  libiconv, botan2, systemd, pkg-config, udns, coreutils, python3Packages } :
+{ lib, stdenv, fetchurl, fetchgit, cmake, libuuid, expat, sqlite, libidn
+, libiconv, botan2, systemd, pkg-config, udns, python3Packages } :
 
+let
+  louiz_catch = fetchgit {
+    url = "https://lab.louiz.org/louiz/Catch.git";
+    rev = "0a34cc201ef28bf25c88b0062f331369596cb7b7"; # v2.2.1
+    sha256 = "0ad0sjhmzx61a763d2ali4vkj8aa1sbknnldks7xlf4gy83jfrbl";
+  };
+in
 stdenv.mkDerivation rec {
   pname = "biboumi";
   version = "9.0";
@@ -10,22 +17,16 @@ stdenv.mkDerivation rec {
     sha256 = "1jvygri165aknmvlinx3jb8cclny6cxdykjf8dp0a3l3228rmzqy";
   };
 
-  louiz_catch = fetchgit {
-    url = "https://lab.louiz.org/louiz/Catch.git";
-    rev = "0a34cc201ef28bf25c88b0062f331369596cb7b7"; # v2.2.1
-    sha256 = "0ad0sjhmzx61a763d2ali4vkj8aa1sbknnldks7xlf4gy83jfrbl";
-  };
-
   patches = [ ./catch.patch ];
 
   nativeBuildInputs = [ cmake pkg-config python3Packages.sphinx ];
-  buildInputs = [ libuuid expat sqlite libiconv libidn botan2 systemd
-    udns ];
+  buildInputs = [ libuuid expat sqlite libiconv libidn botan2 systemd udns ];
+
   buildFlags = [ "all" "man" ];
 
   preConfigure = ''
     substituteInPlace CMakeLists.txt --replace /etc/biboumi $out/etc/biboumi
-    cp $louiz_catch/single_include/catch.hpp tests/
+    cp ${louiz_catch}/single_include/catch.hpp tests/
   '';
 
   doCheck = true;
diff --git a/pkgs/tools/text/csvkit/default.nix b/pkgs/tools/text/csvkit/default.nix
index 05e0cf119bf..1e1018ae56d 100644
--- a/pkgs/tools/text/csvkit/default.nix
+++ b/pkgs/tools/text/csvkit/default.nix
@@ -11,7 +11,7 @@ python3.pkgs.buildPythonApplication rec {
 
   patches = [
     # Fixes a failing dbf related test. Won't be needed on 1.0.6 or later.
-    (fetchpatch{
+    (fetchpatch {
       url = "https://github.com/wireservice/csvkit/commit/5f22e664121b13d9ff005a9206873a8f97431dca.patch";
       sha256 = "1kg00z65x7l6dnm5nfsr5krs8m7mv23hhb1inkaqf5m5fpkpnvv7";
     })
@@ -23,17 +23,22 @@ python3.pkgs.buildPythonApplication rec {
     agate-dbf
     agate-sql
     six
-    setuptools  # `csvsql` requires pkg_resources https://github.com/NixOS/nixpkgs/issues/93594
+    setuptools
   ];
 
   checkInputs = with python3.pkgs; [
-    nose pytestCheckHook
+    nose
+    pytestCheckHook
   ];
 
+  pythonImportsCheck = [ "csvkit" ];
+
   meta = with lib; {
     description = "A suite of command-line tools for converting to and working with CSV";
     maintainers = with maintainers; [ vrthra ];
     license = licenses.mit;
     homepage = "https://github.com/wireservice/csvkit";
+    # FAIL: test_to_sql_create_statement_with_schema (tests.test_agatesql.TestSQL)
+    broken = true;
   };
 }
diff --git a/pkgs/top-level/php-packages.nix b/pkgs/top-level/php-packages.nix
index c2ed5395e35..96d3e9b423b 100644
--- a/pkgs/top-level/php-packages.nix
+++ b/pkgs/top-level/php-packages.nix
@@ -402,7 +402,7 @@ lib.makeScope pkgs.newScope (self: with self; {
         buildInputs = [ pcre' ] ++ lib.optionals (lib.versionAtLeast php.version "8.0") [
           valgrind.dev
         ];
-        patches = [] ++ lib.optionals (lib.versionOlder php.version "7.4") [
+        patches = lib.optionals (lib.versionOlder php.version "7.4") [
           (pkgs.writeText "zend_file_cache_config.patch" ''
             --- a/ext/opcache/zend_file_cache.c
             +++ b/ext/opcache/zend_file_cache.c