store: delete obsolete lsof-disabling code

Since Ifa0adda7984e, we don't use this code anymore on macOS, so we have
no reason to have a knob to disable it anymore.

Change-Id: Ie29a8a8978d9aefd4551895f4f9b3cc0827496df

2 files changed, 13 insertions, 18 deletions

diff --git a/doc/manual/src/contributing/testing.md b/doc/manual/src/contributing/testing.md
index 84836b891..b6b5318e0 100644
--- a/doc/manual/src/contributing/testing.md
+++ b/doc/manual/src/contributing/testing.md
@@ -433,9 +433,6 @@ I grepped `src/` for `get[eE]nv\("` to find the mentions in Lix code.
 - `NIX_PROFILE` - Selects which profile `nix-env` will operate on. Documented elsewhere.
 - `NIX_SSHOPTS` - Options passed to `ssh(1)` when using a ssh remote store.
   Incorrectly documented on `nix-copy-closure` which is *surely* not the only place they are used??
-- `_NIX_TEST_NO_LSOF` - Used on non-Linux, non-macOS platforms to disable using `lsof` when finding gc roots.
-
-  Since https://git.lix.systems/lix-project/lix/issues/156 was fixed, this should probably just be removed as it was a bad workaround for a macOS issue.
 - `_NIX_TEST_GC_SYNC_1` - Path to a pipe that is used to block the GC briefly to validate invariants from the test suite.
 - `_NIX_TEST_GC_SYNC_2` - Path to a pipe that is used to block the GC briefly to validate invariants from the test suite.
 - `_NIX_TEST_FREE_SPACE_FILE` - Path to a file containing a decimal number with the free space that the GC is to believe it has.
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index d58e3c8eb..02234d404 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -321,22 +321,20 @@ Roots LocalStore::findRoots(bool censor)
 
 void LocalStore::findPlatformRoots(UncheckedRoots & unchecked)
 {
-    // lsof is really slow on OS X. This actually causes the gc-concurrent.sh test to fail.
-    // See: https://github.com/NixOS/nix/issues/3011
-    // Because of this we disable lsof when running the tests.
-    if (getEnv("_NIX_TEST_NO_LSOF") != "1") {
-        try {
-            std::regex lsofRegex(R"(^n(/.*)$)");
-            auto lsofLines =
-                tokenizeString<std::vector<std::string>>(runProgram(LSOF, true, { "-n", "-w", "-F", "n" }), "\n");
-            for (const auto & line : lsofLines) {
-                std::smatch match;
-                if (std::regex_match(line, match, lsofRegex))
-                    unchecked[match[1]].emplace("{lsof}");
-            }
-        } catch (ExecError & e) {
-            /* lsof not installed, lsof failed */
+    // N.B. This is (read: undertested!) fallback code only used for
+    // non-Darwin, non-Linux platforms. Both major platforms have
+    // platform-specific code in src/libstore/platform/
+    try {
+        std::regex lsofRegex(R"(^n(/.*)$)");
+        auto lsofLines =
+            tokenizeString<std::vector<std::string>>(runProgram(LSOF, true, { "-n", "-w", "-F", "n" }), "\n");
+        for (const auto & line : lsofLines) {
+            std::smatch match;
+            if (std::regex_match(line, match, lsofRegex))
+                unchecked[match[1]].emplace("{lsof}");
         }
+    } catch (ExecError & e) {
+        /* lsof not installed, lsof failed */
     }
 }