Upload coverage report by hand

Curl in older Go executors (1.17-) does not support `--retry-all-errors`.  But
Codecov Orb uses that option from v5.4.0.

Replace Codecov Orb with shell commands.

Author: dochang

.circleci/config.yml

@@ -2,7 +2,6 @@ version: 2.1
 
 orbs:
   go: circleci/[email protected]
-  codecov: codecov/[email protected]
 
 jobs:
   MegaLinter:
@@ -39,8 +38,32 @@ jobs:
             - go/test:
                 coverprofile: coverage.txt
                 covermode: atomic
-      - codecov/upload:
-          files: coverage.txt
+
+      - run:
+          name: Upload Coverage Report
+          # Do not use Codecov Orb, download Codecov CLI and upload coverage
+          # report by hand.
+          #
+          # Codecov Orb v5.4.0 added `--retry-all-errors` into Curl command.
+          # That option, which is added in Curl 7.71.0, is not available in Go
+          # executor 1.17-.
+          #
+          # https://github.com/codecov/codecov-circleci-orb/commit/12e27248956a647fe5ca2ad3898fb14cb91f9c4a
+          # https://github.com/codecov/wrapper/commit/61989fd8503ba5dd9b6c3f340d1196ca75d0303b
+          # https://github.com/codecov/wrapper/pull/54
+          # https://daniel.haxx.se/blog/2020/06/24/curl-7-71-0-blobs-and-retries/
+          # https://curl.se/docs/manpage.html#--retry-all-errors
+          command: |
+            CODECOV_BIN="$(mktemp -d)/codecov/bin"
+            # `mktemp` on codecov doesn't support long options, use short
+            # options instead.
+
+            CODECOV="${CODECOV_BIN}/codecov"
+            curl --output "${CODECOV}" --create-dirs --silent --show-error https://cli.codecov.io/latest/alpine/codecov
+            chmod +x "${CODECOV}"
+
+            "${CODECOV}" upload-process --file coverage.txt --slug "${CIRCLE_PROJECT_USERNAME}/${CIRCLE_PROJECT_REPONAME}"
+            # `CIRCLE_PROJECT_ID` is a UUID, do not use it.
 
 workflows:
   CI: