diff --git a/.github/workflows/CICD.yml b/.github/workflows/CICD.yml
index 1fb086fc8..0021c85a5 100644
--- a/.github/workflows/CICD.yml
+++ b/.github/workflows/CICD.yml
@@ -51,7 +51,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # failure mode
         unset FAIL_ON_FAULT ; case '${{ env.STYLE_FAIL_ON_FAULT }}' in
           ''|0|f|false|n|no|off) FAULT_TYPE=warning ;;
@@ -109,7 +109,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # failure mode
         unset FAIL_ON_FAULT ; case '${{ env.STYLE_FAIL_ON_FAULT }}' in
           ''|0|f|false|n|no|off) FAULT_TYPE=warning ;;
@@ -159,7 +159,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # failure mode
         unset FAIL_ON_FAULT ; case '${{ env.STYLE_FAIL_ON_FAULT }}' in
           ''|0|f|false|n|no|off) FAULT_TYPE=warning ;;
@@ -174,7 +174,7 @@ jobs:
         # * determine sub-crate utility list
         UTILITY_LIST="$(./util/show-utils.sh ${CARGO_FEATURES_OPTION})"
         echo UTILITY_LIST=${UTILITY_LIST}
-        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo "-puu_${u}"; done;)"
+        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo -n "-puu_${u} g"; done;)"
         outputs CARGO_UTILITY_LIST_OPTIONS
     - name: Install/setup prerequisites
       shell: bash
@@ -217,7 +217,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # failure mode
         unset FAIL_ON_FAULT ; case '${{ env.STYLE_FAIL_ON_FAULT }}' in
           ''|0|f|false|n|no|off) FAULT_TYPE=warning ;;
@@ -269,7 +269,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # failure mode
         unset FAIL_ON_FAULT ; case '${{ env.STYLE_FAIL_ON_FAULT }}' in
           ''|0|f|false|n|no|off) FAULT_TYPE=warning ;;
@@ -284,7 +284,7 @@ jobs:
         # * determine sub-crate utility list
         UTILITY_LIST="$(./util/show-utils.sh ${CARGO_FEATURES_OPTION})"
         echo UTILITY_LIST=${UTILITY_LIST}
-        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo "-puu_${u}"; done;)"
+        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo -n "-puu_${u} "; done;)"
         outputs CARGO_UTILITY_LIST_OPTIONS
     - name: Install `rust` toolchain
       uses: actions-rs/toolchain@v1
@@ -314,7 +314,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # target-specific options
         # * CARGO_FEATURES_OPTION
         unset CARGO_FEATURES_OPTION
@@ -562,7 +562,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # toolchain
         TOOLCHAIN="stable" ## default to "stable" toolchain
         # * specify alternate/non-default TOOLCHAIN for *-pc-windows-gnu targets; gnu targets on Windows are broken for the standard *-pc-windows-msvc toolchain (refs: GH:rust-lang/rust#47048, GH:rust-lang/rust#53454, GH:rust-lang/cargo#6754)
@@ -691,11 +691,11 @@ jobs:
       shell: bash
       run: |
         ## Dependent VARs setup
-        outputs() { step_id="dep_vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="dep_vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # * determine sub-crate utility list
         UTILITY_LIST="$(./util/show-utils.sh ${{ steps.vars.outputs.CARGO_FEATURES_OPTION }})"
         echo UTILITY_LIST=${UTILITY_LIST}
-        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo "-puu_${u}"; done;)"
+        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo -n "-puu_${u} "; done;)"
         outputs CARGO_UTILITY_LIST_OPTIONS
     - name: Info
       shell: bash
@@ -970,7 +970,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # toolchain
         TOOLCHAIN="nightly" ## default to "nightly" toolchain (required for certain required unstable compiler flags) ## !maint: refactor when stable channel has needed support
         # * specify gnu-type TOOLCHAIN for windows; `grcov` requires gnu-style code coverage data files
@@ -1022,10 +1022,10 @@ jobs:
       shell: bash
       run: |
         ## Dependent VARs setup
-        outputs() { step_id="dep_vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="dep_vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # * determine sub-crate utility list
         UTILITY_LIST="$(./util/show-utils.sh ${{ steps.vars.outputs.CARGO_FEATURES_OPTION }})"
-        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo "-puu_${u}"; done;)"
+        CARGO_UTILITY_LIST_OPTIONS="$(for u in ${UTILITY_LIST}; do echo -n "-puu_${u} "; done;)"
         outputs CARGO_UTILITY_LIST_OPTIONS
     - name: Test uucore
       uses: actions-rs/cargo@v1
@@ -1092,7 +1092,7 @@ jobs:
         ~/.cargo/bin/grcov . --output-type files --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" | sort --unique
         # generate coverage report
         ~/.cargo/bin/grcov . --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"
-        echo ::set-output name=report::${COVERAGE_REPORT_FILE}
+        echo "report=${COVERAGE_REPORT_FILE}" >> $GITHUB_OUTPUT
     - name: Upload coverage results (to Codecov.io)
       uses: codecov/codecov-action@v3
       # if: steps.vars.outputs.HAS_CODECOV_TOKEN
diff --git a/.github/workflows/FixPR.yml b/.github/workflows/FixPR.yml
index 460428a9b..f3525b048 100644
--- a/.github/workflows/FixPR.yml
+++ b/.github/workflows/FixPR.yml
@@ -33,7 +33,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # surface MSRV from CICD workflow
         RUST_MIN_SRV=$(grep -P "^\s+RUST_MIN_SRV:" .github/workflows/CICD.yml | grep -Po "(?<=\x22)\d+[.]\d+(?:[.]\d+)?(?=\x22)" )
         outputs RUST_MIN_SRV
@@ -97,7 +97,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # target-specific options
         # * CARGO_FEATURES_OPTION
         CARGO_FEATURES_OPTION='' ;
diff --git a/.github/workflows/GnuTests.yml b/.github/workflows/GnuTests.yml
index c8fe70e7e..66718149e 100644
--- a/.github/workflows/GnuTests.yml
+++ b/.github/workflows/GnuTests.yml
@@ -23,7 +23,7 @@ jobs:
       shell: bash
       run: |
         ## VARs setup
-        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         # * config
         path_GNU="gnu"
         path_GNU_tests="${path_GNU}/tests"
@@ -125,7 +125,7 @@ jobs:
       run: |
         path_UUTILS='${{ steps.vars.outputs.path_UUTILS }}'
         ## Extract/summarize testing info
-        outputs() { step_id="summary"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo ::set-output name=${var}::${!var}; done; }
+        outputs() { step_id="summary"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
         #
         SUITE_LOG_FILE='${{ steps.vars.outputs.SUITE_LOG_FILE }}'
         ROOT_SUITE_LOG_FILE='${{ steps.vars.outputs.ROOT_SUITE_LOG_FILE }}'
@@ -332,7 +332,7 @@ jobs:
         grcov . --output-type files --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" | sort --unique
         # generate coverage report
         grcov . --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"
-        echo ::set-output name=report::${COVERAGE_REPORT_FILE}
+        echo "report=${COVERAGE_REPORT_FILE}" >> $GITHUB_OUTPUT
     - name: Upload coverage results (to Codecov.io)
       uses: codecov/codecov-action@v3
       with: