diff --git a/pkgs/sagemath-categories/README.rst b/pkgs/sagemath-categories/README.rst
index cbfab7ea2df..81311e5a217 100644
--- a/pkgs/sagemath-categories/README.rst
+++ b/pkgs/sagemath-categories/README.rst
@@ -8,7 +8,7 @@ About SageMath
    "Creating a Viable Open Source Alternative to
     Magma, Maple, Mathematica, and MATLAB"
 
-   Copyright (C) 2005-2020 The Sage Development Team
+   Copyright (C) 2005-2022 The Sage Development Team
 
    https://www.sagemath.org
 
@@ -23,6 +23,12 @@ About this experimental pip-installable source distribution
 This pip-installable source distribution `sagemath-categories` is an experimental distribution of a small part of the Sage Library.  Use at your own risk.  It provides a small subset of the modules of the Sage library ("sagelib", `sagemath-standard`).  It is a superset of the `sagemath-objects` (providing Sage objects, the element/parent framework, categories, the coercion system and the related metaclasses), making various additional categories available without introducing dependencies on additional mathematical libraries.
 
 
+Dependencies
+------------
+
+When building from source, development packages of `gmp`, `mpfr`, and `mpc` are needed.
+
+
 Documentation
 -------------
 
diff --git a/pkgs/sagemath-objects/MANIFEST.in b/pkgs/sagemath-objects/MANIFEST.in
index ee82e1ae64c..981e05fe7b1 100644
--- a/pkgs/sagemath-objects/MANIFEST.in
+++ b/pkgs/sagemath-objects/MANIFEST.in
@@ -53,6 +53,7 @@ include sage/misc/constant_function.*
 include sage/misc/call.*
 include sage/misc/bindable_class.*
 include sage/misc/namespace_package.p*
+include sage/misc/package_dir.py
 
 include sage/misc/verbose.*
 include sage/misc/repr.*
@@ -99,6 +100,7 @@ include sage/misc/randstate.*
 include sage/misc/misc.*              # walltime, cputime
 # graft sage/features
 include sage/misc/package.*
+include sage/misc/sagedoc.py
 
 graft sage/repl
 graft sage/server
diff --git a/pkgs/sagemath-objects/README.rst b/pkgs/sagemath-objects/README.rst
index 8e707fcd489..8058f633654 100644
--- a/pkgs/sagemath-objects/README.rst
+++ b/pkgs/sagemath-objects/README.rst
@@ -8,7 +8,7 @@ About SageMath
    "Creating a Viable Open Source Alternative to
     Magma, Maple, Mathematica, and MATLAB"
 
-   Copyright (C) 2005-2020 The Sage Development Team
+   Copyright (C) 2005-2022 The Sage Development Team
 
    https://www.sagemath.org
 
@@ -23,6 +23,12 @@ About this experimental pip-installable source distribution
 This pip-installable source distribution `sagemath-objects` is an experimental distribution of a small part of the Sage Library.  Use at your own risk.  It provides a small, fundamental subset of the modules of the Sage library ("sagelib", `sagemath-standard`), making Sage objects, the element/parent framework, categories, the coercion system and the related metaclasses available.
 
 
+Dependencies
+------------
+
+When building from source, development packages of `gmp`, `mpfr`, and `mpc` are needed.
+
+
 Documentation
 -------------
 
diff --git a/src/sage/env.py b/src/sage/env.py
index 7d6efd28f5e..6421de5e39a 100644
--- a/src/sage/env.py
+++ b/src/sage/env.py
@@ -398,7 +398,7 @@ def get_cblas_pc_module_name() -> str:
 
 
 default_required_modules = ('fflas-ffpack', 'givaro', 'gsl', 'linbox', 'Singular',
-                            'libpng', 'gdlib', 'm4ri', 'zlib', 'cblas')
+                            'libpng', 'gdlib', 'm4ri', 'zlib', 'cblas', 'ecl')
 
 
 default_optional_modules = ('lapack',)
@@ -481,6 +481,22 @@ def cython_aliases(required_modules=None,
                 from collections import defaultdict
                 pc = defaultdict(list, {'libraries': ['z']})
                 libs = "-lz"
+        elif lib == 'ecl':
+            try:
+                # Determine ecl-specific compiler arguments using the ecl-config script
+                ecl_cflags = subprocess.run([ECL_CONFIG, "--cflags"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stdout.split()
+                ecl_libs = subprocess.run([ECL_CONFIG, "--libs"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stdout.split()
+            except subprocess.CalledProcessError:
+                if required:
+                    raise
+                else:
+                    continue
+            aliases["ECL_CFLAGS"] = list(filter(lambda s: not s.startswith('-I'), ecl_cflags))
+            aliases["ECL_INCDIR"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-I'), ecl_cflags)))
+            aliases["ECL_LIBDIR"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-L'), ecl_libs)))
+            aliases["ECL_LIBRARIES"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-l'), ecl_libs)))
+            aliases["ECL_LIBEXTRA"] = list(filter(lambda s: not s.startswith(('-l','-L')), ecl_libs))
+            continue
         else:
             try:
                 aliases[var + "CFLAGS"] = pkgconfig.cflags(lib).split()
@@ -537,15 +553,6 @@ def uname_specific(name, value, alternative):
     except (ValueError, KeyError):
         pass
 
-    # Determine ecl-specific compiler arguments using the ecl-config script
-    ecl_cflags = subprocess.run([ECL_CONFIG, "--cflags"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stdout.split()
-    aliases["ECL_CFLAGS"] = list(filter(lambda s: not s.startswith('-I'), ecl_cflags))
-    aliases["ECL_INCDIR"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-I'), ecl_cflags)))
-    ecl_libs = subprocess.run([ECL_CONFIG, "--libs"], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True).stdout.split()
-    aliases["ECL_LIBDIR"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-L'), ecl_libs)))
-    aliases["ECL_LIBRARIES"] = list(map(lambda s: s[2:], filter(lambda s: s.startswith('-l'), ecl_libs)))
-    aliases["ECL_LIBEXTRA"] = list(filter(lambda s: not s.startswith(('-l','-L')), ecl_libs))
-
     # NTL
     aliases["NTL_CFLAGS"] = ['-std=c++11']
     aliases["NTL_INCDIR"] = [NTL_INCDIR] if NTL_INCDIR else []