chore(build): reduce binary size by ~8 MB by blib · Pull Request #362 · sipeed/picoclaw

blib · 2026-02-17T13:33:57Z

📝 Description

Reduce binary size by ~8 MB through two changes:

Strip debug symbols — added -s -w to LDFLAGS (-s strips symbol table, -w strips DWARF debug info)
Use stdlib JSON — added -tags stdjson to GOFLAGS so that telego uses encoding/json instead of the github.com/grbit/go-json dependency

🗣️ Type of Change

🐞 Bug fix (non-breaking change which fixes an issue)
✨ New feature (non-breaking change which adds functionality)
📖 Documentation update
⚡ Code refactoring (no functional changes, no api changes)

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👨‍💻 Mostly Human-written (Human lead, AI assisted or none)

🔗 Linked Issue

#346

📚 Technical Context (Skip for Docs)

Reference: https://pkg.go.dev/cmd/link — -s -w flags documentation; telego stdjson build tag
Reasoning: go-json adds ~1 MB to the binary and is only used by telego for marginal JSON performance gains. For an embedded/IoT target like PicoClaw, binary size matters more than JSON serialization speed. Stripping debug symbols is standard practice for release builds.

Signed-off-by: Boris Bliznioukov <blib@mail.com>

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Pull request overview

This PR reduces binary size by approximately 8 MB through two build optimization techniques: stripping debug symbols with -s -w linker flags and using stdlib JSON instead of the heavier go-json dependency via the stdjson build tag. This is particularly valuable for the PicoClaw project's embedded/IoT target where binary size is more critical than marginal JSON performance gains.

Changes:

Added -s -w flags to LDFLAGS to strip symbol table and DWARF debug information
Added -tags stdjson to GOFLAGS to make the telego Telegram library use encoding/json instead of github.com/grbit/go-json

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Signed-off-by: Boris Bliznioukov <blib@mail.com>

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Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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Leeaandrob

PR #362 Deep Review — @blib

Clean, well-documented build optimization. The ~8 MB reduction claim is confirmed locally: 25 MB → 17 MB (32% reduction).

Verification

Checked out branch locally: feat-bin-size
make build — succeeds, binary is 17 MB (vs 25 MB without PR)
file build/picoclaw-linux-amd64 — confirms stripped (symbols removed)
./picoclaw version — version info correctly embedded (v0.1.2-9-g2d876ea, git: 2d876eaa, Build: ..., Go: go1.25.7)
go test ./... -tags stdjson — all tests passing across 14 packages
Verified goreleaser config: tags: [stdjson] + ldflags: [-s -w, ...] + version vars
Verified release workflow: id: setup-go → GOVERSION env var → goreleaser template

Binary Size Breakdown

Build	Size	Delta
Without PR (upstream Makefile)	25 MB	—
With PR (`-s -w` + `stdjson`)	17 MB	-8 MB (32%)

Summary of Findings

MEDIUM (Suggestion, not blocking)

M1: build-all target (Makefile:85-89) uses $(LDFLAGS) but NOT $(GOFLAGS) — cross-compiled binaries from make build-all will miss the stdjson tag (pre-existing issue, but now more impactful)

POSITIVE

32% binary size reduction confirmed — 25 MB → 17 MB
Version info now in goreleaser builds — {{ .Version }}, {{ .ShortCommit }}, {{ .Date }}, {{ .Env.GOVERSION }} were missing before this PR. This is a bonus improvement.
stdjson is the official telego build tag — not a hack, properly supported by the library
All tests pass with the stdjson tag — no functional regression
-s -w is standard practice for Go release builds (Go linker docs, Docker best practices)
Excellent PR description with references to Go linker docs and telego source

Verdict: APPROVE

Focused, low-risk build optimization with measurable impact. Ready to merge.

Leeaandrob · 2026-02-17T16:06:04Z

Makefile

 BUILD_TIME=$(shell date +%FT%T%z)
 GO_VERSION=$(shell $(GO) version | awk '{print $$3}')
-LDFLAGS=-ldflags "-X main.version=$(VERSION) -X main.gitCommit=$(GIT_COMMIT) -X main.buildTime=$(BUILD_TIME) -X main.goVersion=$(GO_VERSION)"
+LDFLAGS=-ldflags "-X main.version=$(VERSION) -X main.gitCommit=$(GIT_COMMIT) -X main.buildTime=$(BUILD_TIME) -X main.goVersion=$(GO_VERSION) -s -w"


[Positive] @blib — Clean addition of -s -w to LDFLAGS. The flags are placed after the -X version vars, which is correct (order does not matter for ldflags, but this reads naturally). Confirmed locally: file output shows stripped and picoclaw version still correctly reports version/commit/build info.

Leeaandrob · 2026-02-17T16:06:04Z

Makefile

 # Go variables
 GO?=go
-GOFLAGS?=-v
+GOFLAGS?=-v -tags stdjson


[M1 — MEDIUM: build-all misses GOFLAGS] @blib — The build target (line 77) uses both $(GOFLAGS) and $(LDFLAGS), but build-all (lines 85-89) only uses $(LDFLAGS):

# build (line 77) - correct: $(GO) build $(GOFLAGS) $(LDFLAGS) -o $(BINARY_PATH) ./$(CMD_DIR) # build-all (line 85) - missing GOFLAGS: GOOS=linux GOARCH=amd64 $(GO) build $(LDFLAGS) -o ... ./$(CMD_DIR)

This means make build-all cross-compiled binaries will NOT use stdjson, will include go-json, and will be ~1 MB larger per platform. This is a pre-existing inconsistency, but now that GOFLAGS carries the stdjson tag, it matters more.

Not blocking since goreleaser (used for actual releases) is correctly configured.

Leeaandrob · 2026-02-17T16:06:04Z

.goreleaser.yaml

+      - -X main.version={{ .Version }}
+      - -X main.gitCommit={{ .ShortCommit }}
+      - -X main.buildTime={{ .Date }}
+      - -X main.goVersion={{ .Env.GOVERSION }}


[Positive — Bonus: Version Info in Release Builds] @blib — The goreleaser config previously had NO ldflags at all, meaning release binaries had empty version info (picoclaw version would show blank or default values). This PR adds both the size optimization AND the version embedding. Nice catch — this was a separate bug that got fixed as a side effect.

Leeaandrob · 2026-02-17T16:10:21Z

@blib take look

Leeaandrob · 2026-02-17T16:12:10Z

@blib take look

blib · 2026-02-17T16:33:45Z

Great!
biggest dependencies are github.com/openai/openai-go/v3 and github.com/anthropics/anthropic-sdk-go both of them because they both shim encoding/json from Go 1.24 which brings around 1Mb of code.
If we can make a requrements for Go version 1.24+ we can shave off another Mb or so.

┌────────────────────────────────────────────────────────────────────────────────┐
│ picoclaw-darwin-arm64                                                          │
├─────────┬─────────────────────────────────────────────────┬────────┬───────────┤
│ PERCENT │ NAME                                            │ SIZE   │ TYPE      │
├─────────┼─────────────────────────────────────────────────┼────────┼───────────┤
│ 17.28%  │ __rodata __DATA_CONST                           │ 2.9 MB │ section   │
│ 10.90%  │ github.com/openai/openai-go/v3                  │ 1.8 MB │ vendor    │
│ 7.20%   │ __rodata __TEXT                                 │ 1.2 MB │ section   │
│ 6.31%   │ net                                             │ 1.1 MB │ std       │
│ 6.21%   │ github.com/anthropics/anthropic-sdk-go          │ 1.0 MB │ vendor    │
│ 6.01%   │ crypto                                          │ 1.0 MB │ std       │
│ 4.56%   │ runtime                                         │ 762 kB │ std       │
│ 3.85%   │                                                 │ 643 kB │ generated │
│ 3.19%   │ github.com/sipeed/picoclaw                      │ 533 kB │ main      │
│ 2.91%   │ github.com/gogo/protobuf                        │ 486 kB │ vendor    │
│ 1.92%   │ github.com/bwmarrin/discordgo                   │ 320 kB │ vendor    │
│ 1.88%   │ __noptrdata __DATA                              │ 314 kB │ section   │
│ 1.17%   │ slices                                          │ 196 kB │ std       │
│ 1.16%   │ __gopclntab __DATA_CONST                        │ 193 kB │ section   │
│ 1.14%   │ github.com/valyala/fasthttp                     │ 190 kB │ vendor    │
│ 1.01%   │ reflect                                         │ 169 kB │ std       │
│ 0.98%   │ github.com/larksuite/oapi-sdk-go/v3             │ 163 kB │ vendor    │
│ 0.83%   │ math                                            │ 138 kB │ std       │
│ 0.80%   │ regexp                                          │ 133 kB │ std       │
│ 0.78%   │ encoding/json                                   │ 130 kB │ std       │
│ 0.66%   │ time                                            │ 109 kB │ std       │
│ 0.64%   │ os                                              │ 107 kB │ std       │
│ 0.63%   │ github.com/chzyer/readline                      │ 106 kB │ vendor    │
│ 0.63%   │ __data __DATA                                   │ 105 kB │ section   │
│ 0.61%   │ github.com/slack-go/slack                       │ 102 kB │ vendor    │

fix(Makefile): update LDFLAGS and GOFLAGS for optimized build size

ad747e8

Signed-off-by: Boris Bliznioukov <blib@mail.com>

Copilot AI review requested due to automatic review settings February 17, 2026 13:33

Copilot started reviewing on behalf of blib February 17, 2026 13:34 View session

Copilot AI reviewed Feb 17, 2026

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blib added 2 commits February 17, 2026 14:55

feat(goreleaser): add 'stdjson' tag to picoclaw build configuration

2d758d7

Signed-off-by: Boris Bliznioukov <blib@mail.com>

feat(goreleaser): enhance build flags with versioning and commit info

2d876ea

Signed-off-by: Boris Bliznioukov <blib@mail.com>

Copilot AI review requested due to automatic review settings February 17, 2026 14:00

Copilot started reviewing on behalf of blib February 17, 2026 14:00 View session

Copilot AI reviewed Feb 17, 2026

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Leeaandrob approved these changes Feb 17, 2026

View reviewed changes

Leeaandrob merged commit 8807d82 into sipeed:main Feb 17, 2026
5 of 6 checks passed

blib deleted the feat-bin-size branch February 17, 2026 22:19

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chore(build): reduce binary size by ~8 MB#362

chore(build): reduce binary size by ~8 MB#362
Leeaandrob merged 3 commits intosipeed:mainfrom
blib:feat-bin-size

blib commented Feb 17, 2026 •

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📝 Description

🗣️ Type of Change

🤖 AI Code Generation

🔗 Linked Issue

📚 Technical Context (Skip for Docs)

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Pull request overview

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Pull request overview

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PR #362 Deep Review — @blib

Verification

Binary Size Breakdown

Summary of Findings

Verdict: APPROVE

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blib commented Feb 17, 2026 •

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