diff --git a/below-fix-metadata.diff b/below-fix-metadata.diff
new file mode 100644
index 0000000..1701fa0
--- /dev/null
+++ b/below-fix-metadata.diff
@@ -0,0 +1,29 @@
+--- below-0.4.0/Cargo.toml	1970-01-01T00:00:01+00:00
++++ below-0.4.0/Cargo.toml	2021-10-27T17:40:41.373826+00:00
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+@@ -108,3 +108,17 @@
+ 
+ [features]
+ enable_backtrace = []
++
++[patch.crates-io]
++cgroupfs = { path = "patched-crates/cgroupfs" }
++common = { path = "patched-crates/below-common", package = "below-common" }
++config = { path = "patched-crates/below-config", package = "below-config" }
++dump = { path = "patched-crates/below-dump", package = "below-dump" }
++libbpf-rs = { path = "patched-crates/libbpf-rs" }
++libbpf-cargo = { path = "patched-crates/libbpf-cargo" }
++model = { path = "patched-crates/below-model", package = "below-model" }
++procfs = { path = "patched-crates/fb_procfs", package = "fb_procfs" }
++store = { path = "patched-crates/below-store", package = "below-store" }
++view = { path = "patched-crates/below-view", package = "below-view" }
++derive = { path = "patched-crates/below_derive", package = "below_derive" }
++render = { path = "patched-crates/below-render", package = "below-render" }
diff --git a/below-patched-crates.patch b/below-patched-crates.patch
new file mode 100644
index 0000000..8b0dfc3
--- /dev/null
+++ b/below-patched-crates.patch
@@ -0,0 +1,167 @@
+diff -Naur a/patched-crates/below-common/Cargo.toml b/patched-crates/below-common/Cargo.toml
+--- a/patched-crates/below-common/Cargo.toml	2021-10-27 13:13:54.321402732 -0700
++++ b/patched-crates/below-common/Cargo.toml	2021-10-27 13:14:01.866441582 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-common"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-common/src/dateutil.rs b/patched-crates/below-common/src/dateutil.rs
+--- a/patched-crates/below-common/src/dateutil.rs	2021-10-27 12:58:23.000000000 -0700
++++ b/patched-crates/below-common/src/dateutil.rs	2021-10-27 13:14:26.157566663 -0700
+@@ -302,7 +302,7 @@
+             let mut default_format = String::new();
+             let mut date_with_defaults = date.clone();
+             let mut use_now = false;
+-            for part in ["S", "M", "HI", "d", "mb", "Yy"] {
++            for part in ["S", "M", "HI", "d", "mb", "Yy"].iter() {
+                 if part
+                     .chars()
+                     .any(|ch| naive_format.contains(&format!("%{}", ch)))
+diff -Naur a/patched-crates/below-config/Cargo.toml b/patched-crates/below-config/Cargo.toml
+--- a/patched-crates/below-config/Cargo.toml	2021-10-27 13:13:54.322402737 -0700
++++ b/patched-crates/below-config/Cargo.toml	2021-10-27 13:14:01.867441588 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-config"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below_derive/Cargo.toml b/patched-crates/below_derive/Cargo.toml
+--- a/patched-crates/below_derive/Cargo.toml	2021-10-27 13:13:54.322402737 -0700
++++ b/patched-crates/below_derive/Cargo.toml	2021-10-27 13:14:01.868441593 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below_derive"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-dump/Cargo.toml b/patched-crates/below-dump/Cargo.toml
+--- a/patched-crates/below-dump/Cargo.toml	2021-10-27 13:13:54.323402742 -0700
++++ b/patched-crates/below-dump/Cargo.toml	2021-10-27 13:14:01.869441598 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-dump"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-model/Cargo.toml b/patched-crates/below-model/Cargo.toml
+--- a/patched-crates/below-model/Cargo.toml	2021-10-27 13:13:54.324402747 -0700
++++ b/patched-crates/below-model/Cargo.toml	2021-10-27 13:14:01.869441598 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-model"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-render/Cargo.toml b/patched-crates/below-render/Cargo.toml
+--- a/patched-crates/below-render/Cargo.toml	2021-10-27 13:13:54.324402747 -0700
++++ b/patched-crates/below-render/Cargo.toml	2021-10-27 13:14:01.869441598 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-render"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-store/Cargo.toml b/patched-crates/below-store/Cargo.toml
+--- a/patched-crates/below-store/Cargo.toml	2021-10-27 13:13:54.324402747 -0700
++++ b/patched-crates/below-store/Cargo.toml	2021-10-27 13:14:01.869441598 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-store"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/below-view/Cargo.toml b/patched-crates/below-view/Cargo.toml
+--- a/patched-crates/below-view/Cargo.toml	2021-10-27 13:13:54.324402747 -0700
++++ b/patched-crates/below-view/Cargo.toml	2021-10-27 13:14:01.870441603 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "below-view"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/cgroupfs/Cargo.toml b/patched-crates/cgroupfs/Cargo.toml
+--- a/patched-crates/cgroupfs/Cargo.toml	2021-10-27 13:13:54.324402747 -0700
++++ b/patched-crates/cgroupfs/Cargo.toml	2021-10-27 13:14:01.870441603 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "cgroupfs"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/fb_procfs/Cargo.toml b/patched-crates/fb_procfs/Cargo.toml
+--- a/patched-crates/fb_procfs/Cargo.toml	2021-10-27 13:13:54.325402752 -0700
++++ b/patched-crates/fb_procfs/Cargo.toml	2021-10-27 13:14:01.870441603 -0700
+@@ -10,7 +10,7 @@
+ # See Cargo.toml.orig for the original contents.
+ 
+ [package]
+-edition = "2021"
++edition = "2018"
+ name = "fb_procfs"
+ version = "0.4.0"
+ authors = ["Daniel Xu <dlxu@fb.com>", "Facebook"]
+diff -Naur a/patched-crates/libbpf-cargo/Cargo.toml b/patched-crates/libbpf-cargo/Cargo.toml
+--- a/patched-crates/libbpf-cargo/Cargo.toml	2021-10-27 13:13:54.325402752 -0700
++++ b/patched-crates/libbpf-cargo/Cargo.toml	2021-10-27 13:14:01.870441603 -0700
+@@ -35,7 +35,7 @@
+ version = "0.12"
+ 
+ [dependencies.libbpf-sys]
+-version = "0.5.0-1"
++version = "0.4.0-2"
+ 
+ [dependencies.memmap2]
+ version = "0.3"
+diff -Naur a/patched-crates/libbpf-rs/Cargo.toml b/patched-crates/libbpf-rs/Cargo.toml
+--- a/patched-crates/libbpf-rs/Cargo.toml	2021-10-27 13:13:54.325402752 -0700
++++ b/patched-crates/libbpf-rs/Cargo.toml	2021-10-27 13:14:01.870441603 -0700
+@@ -24,7 +24,7 @@
+ version = "1.3"
+ 
+ [dependencies.libbpf-sys]
+-version = "0.5.0-1"
++version = "0.4.0-2"
+ 
+ [dependencies.nix]
+ version = "0.22"
+diff -Naur a/patched-crates/libbpf-rs/src/object.rs b/patched-crates/libbpf-rs/src/object.rs
+--- a/patched-crates/libbpf-rs/src/object.rs	2021-10-27 12:58:23.000000000 -0700
++++ b/patched-crates/libbpf-rs/src/object.rs	2021-10-27 13:19:44.254204545 -0700
+@@ -67,7 +67,6 @@
+             pin_root_path: ptr::null(),
+             attach_prog_fd: 0,
+             kconfig: ptr::null(),
+-            btf_custom_path: ptr::null(),
+         }
+     }
+ 
diff --git a/rust-below.spec b/rust-below.spec
index 7078b37..92725f5 100644
--- a/rust-below.spec
+++ b/rust-below.spec
@@ -10,6 +10,7 @@
 # el8 doesn't have these macros
 %global __crates_url https://crates.io/api/v1/crates/
 %global crates_source %{__crates_url}%{crate}/%{version}/download#/%{crate}-%{version}.crate
+%global version_no_tilde %{version}
 %endif
 
 %global forgeurl https://github.com/facebookincubator/below
@@ -23,12 +24,17 @@ Summary:        Interactive tool to view and record historical system data
 License:        ASL 2.0
 URL:            https://crates.io/crates/below
 Source:         %{crates_source}
+# Initial patched metadata
+# Downgrade edition to 2018 and patch a number of crates to use the ones
+# distributed in the vendor tarball; this is meant to to be applied only for
+# EPEL builds
+Patch0:         below-fix-metadata.diff
 
 # Get these from the repo as they aren't included in the crate
 Source1:        %{forgeurl}/raw/v%{version}/etc/below.service
 Source2:        %{forgeurl}/raw/v%{version}/etc/logrotate.conf
 Source3:        %{forgeurl}/raw/v%{version}/README.md#/README-upstream.md
-# vendored dependencies for EPEL
+# patched crates and vendored dependencies for EPEL
 # update with ./update-vendor-tarball.sh after bumping the specfile version
 Source4:        %{crate}-%{version}-vendor.tar.gz
 # EPEL specific doc
@@ -38,6 +44,7 @@ ExclusiveArch:  %{rust_arches}
 
 %if 0%{?el8}
 BuildRequires:  rust-toolset
+BuildRequires:  sed
 # for libbpf-sys
 BuildRequires:  kernel-headers
 BuildRequires:  elfutils-libelf-devel
@@ -99,12 +106,16 @@ Recommends:     logrotate
 %systemd_postun_with_restart %{crate}.service
 
 %prep
+%setup -q -n %{crate}-%{version_no_tilde}
 %if 0%{?el8}
-%setup -q -n %{crate}-%{version}
 %cargo_prep -V 4
+%patch0 -p1
 cp -p %{SOURCE5} README-epel.md
+%ifarch s390x
+# drop opt-level generation to fix s390x OOM problems
+sed -i 's/opt-level=3/opt-level=1/' .cargo/config
+%endif
 %else
-%autosetup -n %{crate}-%{version_no_tilde} -p1
 %cargo_prep
 %endif
 cp -p %{SOURCE3} README.md
diff --git a/sources b/sources
index 771749f..a8a238e 100644
--- a/sources
+++ b/sources
@@ -1,2 +1,2 @@
 SHA512 (below-0.4.0.crate) = ce536583048c4866b890f1298e3ca45071594f10c84b313f566725b747ccccd4ec39ad2d1560a63cebcc4c574989c57d73e64ec9e619ba93bea3b399271ed540
-SHA512 (below-0.4.0-vendor.tar.gz) = b32e92a7b97e4a6dc139779b0435acfd04bc64258152ccc45ebc5d4bdd155d5975a02662bce7ff5af849db5816fd8c3be53d796ba723100977cb0c76d09fc439
+SHA512 (below-0.4.0-vendor.tar.gz) = 841822049b8d3a42135b108a77c9c90e09ce55a8c26390e0e1ea05bab3581be6b05e954ffc49a2e3ca7db3c98048466f51807403847a8e40e222f279a714435f
diff --git a/update-vendor-tarball.sh b/update-vendor-tarball.sh
index ceaffd4..9d10dcb 100755
--- a/update-vendor-tarball.sh
+++ b/update-vendor-tarball.sh
@@ -17,9 +17,35 @@ tardir="$PWD"
 workdir=$(mktemp -d)
 trap 'rm -rf "$workdir"' EXIT
 
+# All the below crates use edition 2021, which isn't supported by rust in el8;
+# moreover, libbpf-rs and libbpf-cargo transitively depend on libbpf 0.5.0, and
+# el8 ships 0.4.0.
+#
+# So we cheat:
+# - below-fix-metadata.diff (which is applied in %prep) downgrades the edition
+#   for below and sets up all the other crates to be replaced with patched
+#   versions under patched-crates/
+# - below-patched-crates.patch contains the actual modifications of the patched
+#   crates (mostly the edition downgrades, a few pins and a couple of build
+#   fixes)
+#
+# We then build the vendored tarball as follows:
+# - unpack the below crate and vendor
+# - foreach patched crate, move it from vendor/ to patched-crates/
+# - delete vendor/ as it's no longer needed, and so we can vendor again later
+# - apply the two patches, to fix the below metadata and the patched crates
+# - run vendor again, and then tar up *both* patched-crates/ and vendor/
 tar xvzf "$tardir/$crate" -C "$workdir"
+(cd "${workdir}/${nv}" && cargo vendor)
+mkdir "${workdir}/${nv}/patched-crates"
+for c in below_derive below-common below-config below-dump below-model below-render below-store below-view cgroupfs fb_procfs libbpf-cargo libbpf-rs; do
+  mv "${workdir}/${nv}/vendor/${c}" "${workdir}/${nv}/patched-crates/"
+done
+rm -r "${workdir}/${nv}/vendor"
 (cd "${workdir}/${nv}" && \
+  patch -p1 < ${tardir}/below-fix-metadata.diff && \
+  patch -p1 < ${tardir}/below-patched-crates.patch && \
   cargo vendor && \
-  tar cvzf "${tardir}/${vendor_tarball}" vendor/)
+  tar cvzf "${tardir}/${vendor_tarball}" patched-crates/ vendor/)
 
 exit 0