Hacktoberfest 2026: as issues que os mantenedores marcaram para outubro, abertas e boas para iniciantes. Ver issues do Hacktoberfest

[Bug] create-new-feature.sh uses ${word^^} (bash 4+) and silently drops acronyms on macOS (bash 3.2)

Aberta Para iniciantes
  • Algo errado?
#3,927 2 comentários 0 reações 0 responsáveis Ver no GitHub

Mantenedores costumam responder em até 1 dia

Ninguém assumiu esta issue ainda.

Avaliação

Dificuldade
2/5
Tempo estimado
1-3 horas
Facilidade para iniciantes
84/100
Tipo de issue
Bug
Clareza
Claramente especificada
Status de atividade
Pouca atividade
Stack de tecnologia
bash
Domínio
cli, tooling

Direção de pesquisa

Comece em .specify/scripts/bash/create-new-feature.sh, por volta da linha 231, e inspecione o caminho do nome da branch para acrônimos. Execute os comandos fornecidos --json --dry-run no /bin/bash 3.2 do macOS e compare com o Bash 5.x. Está concluído quando acrônimos curtos em maiúsculas permanecem em BRANCH_NAME e stderr não contém nenhum aviso de substituição inválida.

Escrita pelo modelo de indexação a partir do texto da issue.

Descrição

bug-assess invalid

Summary

create-new-feature.sh (line 231) uses ${word^^}, a bash 4+ uppercase expansion. macOS ships bash 3.2.57 (Apple's last GPLv2 build) and the script fails silently on that line: stderr is full of bad substitution warnings, the script keeps running, and the generated branch name silently drops acronyms that were short (≤2 chars) and uppercase in the original description.

Because the script still emits valid JSON and the resulting branch name is plausible, end users on macOS get a quietly truncated branch without realizing it.

Environment

  • macOS (any current version; bash 3.2.57 has been the system bash on every macOS since 2007)
  • Any git repo initialised with specify init
  • No bash from Homebrew installed (or installed but not first in PATH for the running shell)
$ /bin/bash --version
GNU bash, version 3.2.57(1)-release (arm64-apple-darwin24)

$ bash .specify/scripts/bash/create-new-feature.sh --json --dry-run \
    "Transparencia Art. 50 AI Act: aviso de interaccion con IA"
{"BRANCH_NAME":"001-transparencia-art-act", ...}      # ← missing "AI"

$ bash .specify/scripts/bash/create-new-feature.sh --json --dry-run "AI Act transparency"
{"BRANCH_NAME":"001-act-transparency", ...}           # ← missing "AI" (top-3 cutoff also affected)
bad substitution                                         # (only visible in stderr; the JSON looks fine)

The same inputs against bash 5.x preserve the acronym:

$ bash .specify/scripts/bash/create-new-feature.sh --json --dry-run "AI Act transparency"
{"BRANCH_NAME":"001-ai-act-transparency", ...}        # ← "ai" preserved

Root cause

create-new-feature.sh, line 231:

elif echo "$description" | grep -q "\b${word^^}\b"; then
    # Keep short words if they appear as uppercase in original (likely acronyms)
    meaningful_words+=("$word")
fi

${word^^} is case-conversion syntax introduced in bash 4.0 (2009). It is not available in bash 3.2. On bash 3.2 the line errors out, grep runs with the literal placeholder string, the grep returns non-zero, the elif is false, and the short word is silently dropped from meaningful_words[]. The same ${var^^} / ${var,,} pattern likely exists in other vendored scripts; I have not audited them all.

The shebang #!/usr/bin/env bash does not protect against this — env picks whatever bash resolves to in the current PATH, and on a stock macOS that is the system's bash 3.2.

Suggested fix

Two options, in order of preference:

  1. POSIX-portable — replace ${word^^} with a portable uppercase conversion, e.g. echo "$word" | tr '[:lower:]' '[:upper:]', so the script works on bash 3.2 too. This is a one-line change per occurrence and removes the silent failure mode entirely.
  2. Bash 4+ required — if the project decides to require bash 4+ intentionally, make the failure loud: at the top of every vendored script, add a runtime check that fails fast with a clear message and a hint to install bash from Homebrew (brew install bash). Currently the failure is silent and the user has no way to know their branch name is wrong.

I'd recommend option 1 (POSIX-portable) — the function is a small, isolated transformation and the project already has a clean_branch_name that uses tr '[:upper:]' '[:lower:]' to do the inverse. Symmetry argues for replacing the bash-only expansion with tr as well.

Workaround on macOS today

Install bash 5.x via Homebrew and ensure it is first in PATH for the shell that runs Spec-Kit:

brew install bash
# ~/.zshrc or ~/.bashrc, idempotent:
case "$PATH" in
  /opt/homebrew/bin:*) ;;
  /opt/homebrew/bin) ;;
  *) export PATH="/opt/homebrew/bin${PATH:+:$PATH}" ;;
esac

Note that on login shells, /etc/zprofile runs path_helper which re-derives PATH from /etc/paths + /etc/paths.d/* and puts /opt/homebrew/bin at the end — so the prefix must be re-asserted in a file that runs after /etc/zprofile (e.g. ~/.zshrc).

Impact

This affects every macOS developer or agent using Spec-Kit with a description containing acronyms (e.g. "AI Act", "RGPD", "GDPR", "API", "OAuth", "HIPAA", "PCI"). The "feature name" used downstream in specs/NNN-short-name/spec.md is the same truncated string, so the spec file itself also loses the acronym, and any tooling that relies on the branch/spec name to understand the feature (e.g. CI labels, dashboards, search) gets the wrong subject.

Discovered while piloting Spec-Kit on ada-legal-ai (PR #11 in the HOILAB org). Same root cause likely affects any other team running Spec-Kit on macOS.

Linguagem predominante
Python
Estrelas
140k
Forks
12.6k
Merge médio
1d 11h
PRs com merge (30d)
184

Preparar o ambiente

Abrir no Codespaces

Inicia o contêiner de desenvolvimento do projeto no navegador, com a sua própria conta do GitHub.

Primeiros passos

  1. Leia a issue inteira e depois o guia de contribuição do projeto.
  2. Comente na issue dizendo que vai assumir — evita que duas pessoas façam o mesmo trabalho.
  3. Faça um fork do repositório e trabalhe em uma branch.
  4. Abra um pull request que referencie o número da issue.

Mais de github/spec-kit

Todas as issues de github/spec-kit

Issues semelhantes

Mais issues de Python

Receba novas issues na sua caixa de entrada

Um resumo curto de issues do GitHub para quem está começando.